Publications 2016
Publications de l'année 2016 :

A conformal bootstrap approach to critical percolation in two dimensions
Marco Picco ^{1} Sylvain Ribault ^{2} Raoul Santachiara ^{3}
SciPost Physics, 2016, <10.21468/SciPostPhys.1.1.009>
We study fourpoint functions of critical percolation in two dimensions, and more generally of the Potts model. We propose an exact ansatz for the spectrum: an infinite, discrete and nondiagonal combination of representations of the Virasoro algebra. Based on this ansatz, we compute fourpoint functions using a numerical conformal bootstrap approach. The results agree with MonteCarlo computations of connectivities of random clusters.
 1. LPTHE  Laboratoire de Physique Théorique et Hautes Energies
 2. IPHT  Institut de Physique Théorique  UMR CNRS 3681
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

A Materials Perspective on Casimir and van der Waals Interactions
L. M. Woods ^{1} D. A. R. Dalvit ^{2} A. Tkatchenko ^{3, 4} P. RodriguezLopez ^{5} A. W. Rodriguez ^{6} R. Podgornik ^{7, 8, 9}
Reviews of Modern Physics, American Physical Society, 2016, 88, pp.045003
Interactions induced by electromagnetic fluctuations, such as van der Waals and Casimir forces, are of universal nature present at any length scale between any types of systems with finite dimensions. Such interactions are important not only for the fundamental science of materials behavior, but also for the design and improvement of micro and nanostructured devices. In the past decade, many new materials have become available, which has stimulated the need of understanding their dispersive interactions. The field of van der Waals and Casimir forces has experienced an impetus in terms of developing novel theoretical and computational methods to provide new insights in related phenomena. The understanding of such forces has far reaching consequences as it bridges concepts in materials, atomic and molecular physics, condensed matter physics, high energy physics, chemistry and biology. In this review, we summarize major breakthroughs and emphasize the common origin of van der Waals and Casimir interactions. We examine progress related to novel ab initio modeling approaches and their application in various systems, interactions in materials with Diraclike spectra, force manipulations through nontrivial boundary conditions, and applications of van der Waals forces in organic and biological matter. The outlook of the review is to give the scientific community a materials perspective of van der Waals and Casimir phenomena and stimulate the development of experimental techniques and applications.
 1. USF  University of South Florida
 2. Theoretical Division [LANL]
 3. FHI  FritzHaberInstitut der MaxPlanckGesellschaft [Berlin]
 4. University of Luxembourg [Luxembourg]
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. Princeton University, Princeton, NJ 08544, USA
 7. University of Massachusetts
 8. IJS  Jozef Stefan Institute [Ljubljana, Slovenia]
 9. University of Ljubljana (SLOVENIA)

Anisotropic collisions of dipolar Bose–Einstein condensates in the universal regime
Nathaniel Q Burdick ^{1} Andrew G Sykes ^{2} Yijun Tang ^{1} Benjamin L Lev ^{1}
New Journal of Physics, Institute of Physics: Open Access Journals, 2016, 18 (11), pp.113004
 1. Stanford University [Stanford]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Anisotropic Expansion of a Thermal Dipolar Bose Gas
Y. Tang ^{1, 2} A. g. Sykes ^{3} N. q. Burdick ^{2, 1} J. m. Disciacca ^{2, 1} D. s. Petrov ^{3} B. l. Lev ^{2, 1}
Physical Review Letters, American Physical Society, 2016, 117 (15), pp.155301
 1. Edward L Ginzton Laboratory
 2. Stanford University [Stanford]
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Antiperiodic dynamical 6vertex model by separation of variables II: functional equations and form factors
Damien LevyBencheton ^{1} Giuliano Niccoli ^{2} Véronique Terras ^{3}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, 2016 (3), <http://iopscience.iop.org/article/10.1088/17425468/2016/03/033110/meta>. <10.1088/17425468/2016/03/033110>
We pursue our study of the antiperiodic dynamical 6vertex model using Sklyanin's separation of variables approach, allowing in the model new possible global shifts of the dynamical parameter. We show in particular that the spectrum and eigenstates of the antiperiodic transfer matrix are completely characterized by a system of discrete equations. We prove the existence of different reformulations of this characterization in terms of functional equations of Baxter's type. We notably consider the homogeneous functional TQ equation which is the continuous analog of the aforementioned discrete system and show, in the case of a model with an even number of sites, that the complete spectrum and eigenstates of the antiperiodic transfer matrix can equivalently be described in terms of a particular class of its Qsolutions, hence leading to a complete system of Bethe equations. Finally, we compute the form factors of local operators for which we obtain determinant representations in finite volume.
 1. IMB  Institut de Mathématiques de Bourgogne [Dijon]
 2. PhysENS  Laboratoire de Physique de l'ENS Lyon
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Archive ouverte HAL – L’entraînement cognitivoperceptif basé sur la vidéo et ses modes d’instructions
Nicolas Milazzo ^{1} Marjorie Bernier ^{2} E. RosnetD. FarrowJ.F. Fournier
Nicolas Milazzo, Marjorie Bernier, E. Rosnet, D. Farrow, J.F. Fournier. L’entraînement cognitivoperceptif basé sur la vidéo et ses modes d’instructions. Psychologie Française, Elsevier Masson, 2016, 61 (4), pp.273289. ⟨10.1016/j.psfr.2015.07.004⟩. ⟨hal02512758⟩
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. CREAD EA 3875  Centre de Recherche sur l'Education, les apprentissages et la didactique

Archive ouverte HAL – Schrödinger Approach to Mean Field Games
Igor Swiecicki ^{1} Thierry Gobron ^{2} Denis Ullmo ^{3}
Igor Swiecicki, Thierry Gobron, Denis Ullmo. Schrödinger Approach to Mean Field Games. Physical Review Letters, American Physical Society, 2016, 116 (12), ⟨10.1103/PhysRevLett.116.128701⟩. ⟨hal02923129⟩
 1. LPTM  UMR 8089  Laboratoire de Physique Théorique et Modélisation
 2. LPP  Laboratoire Paul Painlevé  UMR 8524
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model
Hervé Petetin ^{1, 2} Jean Sciare ^{3} Michael Bressi ^{4} Valérie Gros ^{4} Amandine Rosso ^{5} Olivier Sanchez ^{6} Roland SardaEstève ^{4} JeanEudes Petit ^{7} Matthias Beekmann ^{8}
Atmospheric Chemistry and Physics, European Geosciences Union, 2016, 16 (16), pp.10419  10440. 〈10.5194/acp16104192016〉
 1. Surveillance de la qualité de l'air en ÎledeFrance
 2. LISA  Laboratoire interuniversitaire des systèmes atmosphèriques
 3. CyI  Cyprus Institute
 4. LSCE  Laboratoire des Sciences du Climat et de l'Environnement [GifsurYvette]
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. Hôpital européen Georges Pompidou
 7. LIRIS  Laboratoire d'InfoRmatique en Image et Systèmes d'information
 8. CNRS  Centre National de la Recherche Scientifique

Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model – Archive ouverte HAL
Hervé Petetin ^{1, 2} Jean Sciare ^{3} Michael Bressi ^{4} Valérie Gros ^{4, 5} Amandine Rosso ^{6} Olivier Sanchez ^{7} Roland SardaEstève ^{4, 5} JeanEudes Petit ^{4, 5} Matthias Beekmann ^{8}
Hervé Petetin, Jean Sciare, Michael Bressi, Valérie Gros, Amandine Rosso, et al.. Assessing the ammonium nitrate formation regime in the Paris megacity and its representation in the CHIMERE model. Atmospheric Chemistry and Physics, European Geosciences Union, 2016, 16 (16), pp.10419  10440. ⟨10.5194/acp16104192016⟩. ⟨hal01587430⟩
Secondary inorganic compounds represent a major fraction of fine aerosol in the Paris megacity. The thermodynamics behind their formation is now relatively well constrained but, due to sparse direct measurements of their precursors (in particular NH 3 and HNO 3), uncertainties remain on their concentrations and variability as well as the formation regime of ammonium nitrate (in terms of limited species among NH 3 and HNO 3) in urban environments such as Paris. This study presents the first urban background measurements of both inorganic aerosol compounds and their gaseous precursors during several months within the city of Paris. Intense agriculturerelated NH 3 episodes are observed in spring/summer while HNO 3 concentrations remain relatively low, even during summer, which leads to a NH 3rich regime in Paris. The local formation of ammonium nitrate within the city appears low, despite high NO x emissions. The data set also allows evaluating the CHIMERE chemistrytransport model (CTM). Interestingly, the rather good results obtained on ammonium nitrates hide significant errors on gaseous precursors (e.g., mean bias of −75 and +195 % for NH 3 and HNO 3 , respectively). This leads to a misrepresentation of the nitrate formation regime through a highly underestimated gas ratio metric (introduced by Ansari and Pandis, 1998) and a much higher sensitivity of nitrate concentrations to ammonia changes. Several uncertainty sources are investigated , pointing out the importance of better assessing both NH 3 agricultural emissions and OH concentrations in the future. These results remind us of the caution required when using of CTMs for emission scenario analysis, highlighting the importance of prior diagnostic and dynamic evaluations.
 1. AIRPARIF  Surveillance de la qualité de l'air en ÎledeFrance
 2. LISA (UMR_7583)  Laboratoire Interuniversitaire des Systèmes Atmosphériques
 3. CyI  Cyprus Institute
 4. LSCE  Laboratoire des Sciences du Climat et de l'Environnement [GifsurYvette]
 5. CAE  Chimie Atmosphérique Expérimentale
 6. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 7. HEGP  Hôpital Européen Georges Pompidou [APHP]
 8. CNRS  Centre National de la Recherche Scientifique

Asymptotic control theory for a system of linear oscillators
Aleksey Fedorov ^{1} Alexander Ovseevich ^{2}
Moscow mathematical journal, 2016, 16 (3), pp.561
We present an asymptotic control theory for a system of an arbitrary number of linear oscillators under a common bounded control. We suggest a design method of a feedback control for this system. By using the DiPernaLions theory of singular ODEs, we prove that the suggested control law correctly defines the motion of the system. The obtained control is asymptotically optimal: the ratio of the motion time to zero under this control to the minimum one is close to 1 if the initial energy of the system is large. The results are partially based on a new perturbation theory of observable linear systems.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. institute for Problems in Mechanics [Moscow]

Average diagonal entropy in nonequilibrium isolated quantum systems
Olivier Giraud ^{1} Ignacio GarcíaMata ^{2}
Physical Review E , American Physical Society (APS), 2016, 94 (1), pp.012122
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Instituto de Investigaciones Físicas de Mar del Plata

Bending stiff charged polymers: the electrostatic persistence length
E. Trizac ^{1} T. Shen ^{2}
EPL  Europhysics Letters, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2016, 116, pp.18007
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. The University of Tennessee [Knoxville]

Bidirectional imperfect quantum teleportation with a single Bell state
E. O. Kiktenko ^{1, 2} A. A. Popov ^{2} A. K. Fedorov ^{3, 4}
Physical Review A, American Physical Society, 2016, 93, pp.062305
We present a bidirectional modification of the standard onequbit teleportation protocol, where both Alice and Bob transfer noisy versions of their qubit states to each other by using single Bell state and auxiliary (trigger) qubits. Three schemes are considered: the first where the actions of parties are governed by two independent quantum random triggers, the second with single random trigger, and the third as a mixture of the first two. We calculate the fidelities of teleportation for all schemes and find a condition on correlation between trigger qubits in the mixed scheme which allows us to overcome the classical fidelity boundary of 2/3. We apply the ChoiJamiolkowski isomorphism to the quantum channels obtained in order to investigate an interplay between their ability to transfer the information, entanglementbreaking property, and auxiliary classical communication needed to form correlations between trigger qubits. The suggested scheme for bidirectional teleportation can be realized by using current experimental tools.
 1. Schmidt Institute of Physics of the Earth, RAS Moscou
 2. Bauman Moscow State Technical University
 3. Russian Quantum Center
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Bound states in string nets
Marc SchulzSebastien DusuelJulien Vidal ^{1}
Phys.Rev., 2016, B94 (20), pp.205102. 〈10.1103/PhysRevB.94.205102〉
We discuss the emergence of bound states in the lowenergy spectrum of the stringnet Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zerotension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zerotension limit.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Composite operators in Cubic Field Theories and Link Overlap Fluctuations in SpinGlass Models
Ada Altieri ^{1, 2} Giorgio Parisi ^{2} Tommaso Rizzo ^{2}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 93, pp.024422
We present a complete characterization of the fluctuations and correlations of the squared overlap in the EdwardsAnderson SpinGlass model in zero field. The analysis reveals that the energyenergy correlations (and thus the specific heat) have a different critical behavior than the fluctuations of the link overlap in spite of the fact that the average energy and average link overlap have the same critical properties. More precisely the linkoverlap fluctuations are larger than the specific heat according to a computation at first order in the $6\epsilon$ expansion. An unexpected outcome is that the linkoverlap fluctuations have a subdominant powerlaw contribution characterized by an anomalous logarithmic prefactor which is missing in the specific heat. In order to compute the $\epsilon$ expansion we consider the problem of the renormalization of quadratic composite operators in a generic multicomponent cubic field theory: the results obtained have a range of applicability beyond spinglass theory.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Dipartimento di Fisica and INFM

Convex hulls of multiple random walks: A largedeviation study
Timo Dewenter ^{1} Gunnar Claussen ^{2, 1} Alexander K. Hartmann ^{1} Satya N. Majumdar ^{3}
Physical Review E , American Physical Society (APS), 2016, 94 (5), pp.052120
 1. Institut für Physik
 2. FH Oldenburg/Ostfriesland/Wilhelmshaven
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Correlation and fluctuation in Random Average Process on an infinite line with a driven tracer
J. Cividini ^{1} A. Kundu ^{2} S. N. Majumdar ^{3} D. Mukamel ^{1}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, pp.053212
We study the effect of single biased tracer particle in a bath of other particles performing the random average process (RAP) on an infinite line. We focus on the large time behavior of the mean and the fluctuations of the positions of the particles and also the correlations among them. In the large time t limit these quantities have welldefined scaling forms and grow with time as $\sqrt{t}$. A differential equation for the scaling function associated with the correlation function is obtained and solved perturbatively around the solution for a symmetric tracer. Interestingly, when the tracer is totally asymmetric, further progress is enabled by the fact that the particles behind of the tracer do not affect the motion of the particles in front of it, which leads in particular to an exact expression for the variance of the position of the tracer. Finally, the variance and correlations of the gaps between successive particles are also studied. Numerical simulations support our analytical results.
 1. Weizmann Institute
 2. International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Correlation functions with fusionchannel multiplicity in W 3 $$ {\mathcal{W}}_3 $$ Toda field theory
Vladimir Belavin ^{1, 2} Benoit Estienne ^{3} Omar Foda ^{4} Raoul Santachiara ^{5}
Journal of High Energy Physics, Springer, 2016, 2016 (6), pp.137
 1. IITP  Institute for Information Transmission Problems
 2. P. N. Lebedev Physical Institute [Moscow]
 3. LPTHE  Laboratoire de Physique Théorique et Hautes Energies
 4. University of Melbourne
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Crossing probability for directed polymers in random media. II. exact tail of the distribution
Andrea De Luca ^{1} Pierre Le Doussal ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2016, 93, pp.032118. <10.1103/PhysRevE.93.032118>
We study the probability $p \equiv p_\eta(t)$ that two directed polymers in a given random potential $\eta$ and with fixed and nearby endpoints, do not cross until time $t$. This probability is itself a random variable (over samples $\eta$) which, as we show, acquires a very broad probability distribution at large time. In particular the moments of $p$ are found to be dominated by atypical samples where $p$ is of order unity. Building on a formula established by us in a previous work using nested Bethe Ansatz and Macdonald process methods, we obtain analytically the leading large time behavior of {\it all moments} $\overline{p^m}\simeq \gamma_m/t$. From this, we extract the exact tail $\sim \rho(p)/t$ of the probability distribution of the noncrossing probability at large time. The exact formula is compared to numerical simulations, with excellent agreement.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS

Dispersive hydrodynamics of nonlinear polarization waves in twocomponent BoseEinstein condensates
T. Congy ^{1} A. M. Kamchatnov ^{2} N. Pavloff ^{1}
SciPost Physics, 2016, 1 (1), pp.006
We study one dimensional mixtures of twocomponent BoseEinstein condensates in the limit where the intraspecies and interspecies interaction constants are very close. Near the mixingdemixing transition the polarization and the density dynamics decouple. We study the nonlinear polarization waves, show that they obey a universal (i.e., parameter free) dynamical description, identify a new type of algebraic soliton, explicitly write simple wave solutions, and study the GurevichPitaevskii problem in this context.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Institute of Spectroscopy

Distribution of spectral linear statistics on random matrices beyond the large deviation function — Wigner time delay in multichannel disordered wires
Aurélien Grabsch ^{1} Christophe Texier ^{1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49 (20), pp.465002
An invariant ensemble of $N\times N$ random matrices can be characterised by a joint distribution for eigenvalues $P(\lambda_1,\cdots,\lambda_N)$. The study of the distribution of linear statistics, i.e. of quantities of the form $L=(1/N)\sum_if(\lambda_i)$ where $f(x)$ is a given function, appears in many physical problems. In the $N\to\infty$ limit, $L$ scales as $L\sim N^\eta$, where the scaling exponent $\eta$ depends on the ensemble and the function $f$. Its distribution can be written under the form $P_N(s=N^{\eta}\,L)\simeq A_{\beta,N}(s)\,\exp\big\{(\beta N^2/2)\,\Phi(s)\big\}$, where $\beta\in\{1,\,2,\,4\}$ is the Dyson index. The Coulomb gas technique naturally provides the large deviation function $\Phi(s)$, which can be efficiently obtained thanks to a "thermodynamic identity" introduced earlier. We conjecture the preexponential function $A_{\beta,N}(s)$. We check our conjecture on several well controlled cases within the Laguerre and the Jacobi ensembles. Then we apply our main result to a situation where the large deviation function has no minimum (and $L$ has infinite moments)~: this arises in the statistical analysis of the Wigner time delay for semiinfinite multichannel disordered wires (Laguerre ensemble). The statistical analysis of the Wigner time delay then crucially depends on the preexponential function $A_{\beta,N}(s)$, which ensures the decay of the distribution for large argument.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Dropping the independence: singular values for products of two coupled random matrices
Gernot Akemann ^{1, 2} Eugene Strahov ^{3}
Communications in Mathematical Physics, Springer Verlag, 2016, 345 (1), pp.101
We study the singular values of the product of two coupled rectangular random matrices as a determinantal point process. Each of the two factors is given by a parameter dependent linear combination of two independent, complex Gaussian random matrices, which is equivalent to a coupling of the two factors via an ItzyksonZuber term. We prove that the squared singular values of such a product form a biorthogonal ensemble and establish its exact solvability. The parameter dependence allows us to interpolate between the singular value statistics of the Laguerre ensemble and that of the product of two independent complex Ginibre ensembles which are both known. We give exact formulae for the correlation kernel in terms of a complex double contour integral, suitable for the subsequent asymptotic analysis. In particular, we derive a ChristoffelDarboux type formula for the correlation kernel, based on a five term recurrence relation for our biorthogonal functions. It enables us to find its scaling limit at the origin representing a hard edge. The resulting limiting kernel coincides with the universal Meijer Gkernel found by several authors in different ensembles. We show that the central limit theorem holds for the linear statistics of the singular values and give the limiting variance explicitly.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Fakultät für Physik
 3. HEBREW UNIVERSITY  Dept. Of Mathematics, Hebrew University

Electromagnetic Casimir energy of a disk opposite a plane
Thorsten Emig ^{1, 2, 3} Noah Graham ^{4}
Physical Review A, American Physical Society, 2016, 94 (3), pp.032509
 1. (MSC)2 UMI3466 CNRSMIT  MultiScale Material Science for Energy and Environment
 2. Massachussetts Institute of Technology
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Middlebury College

Energy transport between two integrable spin chains
Alberto Biella ^{1, 2} Andrea De Luca ^{3} Jacopo Viti ^{4} Davide Rossini ^{2, 1} Leonardo Mazza ^{5, 2} Rosario Fazio ^{6, 2, 1}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 93, pp.205121
We study the energy transport in a system of two halfinfinite XXZ chains initially kept separated at different temperatures, and later connected and let free to evolve unitarily. By changing independently the parameters of the two halves, we highlight, through bosonisation and timedependent matrixproductstate simulations, the different contributions of lowlying bosonic modes and of fermionic quasiparticles to the energy transport. In the simulations we also observe that the energy current reaches a finite value which only slowly decays to zero. The general pictures that emerges is the following. Since integrability is only locally broken in this model, a preequilibration behaviour may appear. In particular, when the sound velocities of the bosonic modes of the two halves match, the lowtemperature energy current is almost stationary and described by a formula with a nonuniversal prefactor interpreted as a transmission coefficient. Thermalisation, characterized by the absence of any energy flow, occurs only on longer timescales which are not accessible with our numerics.
 1. Kavli Institute for Theoretical Physics
 2. SNS  Scuola Normale Superiore di Pisa
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. UFRN  Universidade Federal do Rio Grande do Norte [Natal]
 5. Departement de PhysiqueENS
 6. ICTP  International Center for Theoretical Physics [Trieste]

Engineered swift equilibration of a Brownian particle
Ignacio Martinez ^{1} Artyom Petrosyan ^{1} David GuéryOdelin ^{2} Emmanuel Trizac ^{3} Sergio Ciliberto ^{1}
Nature Physics, Nature Publishing Group, 2016, 12, pp.843846. <10.1038/nphys3758>
A fundamental and intrinsic property of any device or natural system is its relaxation time relax, which is the time it takes to return to equilibrium after the sudden change of a control parameter [1]. Reducing τ relax , is frequently necessary, and is often obtained by a complex feedback process. To overcome the limitations of such an approach, alternative methods based on driving have been recently demonstrated [2, 3], for isolated quantum and classical systems [4–9]. Their extension to open systems in contact with a thermostat is a stumbling block for applications. Here, we design a protocol,named Engineered Swift Equilibration (ESE), that shortcuts timeconsuming relaxations, and we apply it to a Brownian particle trapped in an optical potential whose properties can be controlled in time. We implement the process experimentally, showing that it allows the system to reach equilibrium times faster than the natural equilibration rate. We also estimate the increase of the dissipated energy needed to get such a time reduction. The method paves the way for applications in micro and nano devices, where the reduction of operation time represents as substantial a challenge as miniaturization [10]. The concepts of equilibrium and of transformations from an equilibrium state to another, are cornerstones of thermodynamics. A textbook illustration is provided by the expansion of a gas, starting at equilibrium and expanding to reach a new equilibrium in a larger vessel. This operation can be performed either very slowly by a piston, without dissipating energy into the environment, or alternatively quickly, letting the piston freely move to reach the new volume.
 1. PhysENS  Laboratoire de Physique de l'ENS Lyon
 2. Atomes Froids (LCAR)
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Equilibration Properties of Classical Integrable Field Theories
Andrea De Luca ^{1} Giuseppe Mussardo ^{2, 3}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, 064011
We study the equilibration properties of classical integrable field theories at a finite energy density, with a time evolution that starts from initial conditions far from equilibrium. These classical field theories may be regarded as quantum field theories in the regime of high occupation numbers. This observation permits to recover the classical quantities from the quantum ones by taking a proper $\hbar \rightarrow 0$ limit. In particular, the time averages of the classical theories can be expressed in terms of a suitable version of the LeClairMussardo formula relative to the Generalized Gibbs Ensemble. For the purposes of handling time averages, our approach provides a solution of the problem of the {\em infinite gap solutions} of the Inverse Scattering Method.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. SISSA / ISAS  Scuola Internazionale Superiore di Studi Avanzati / International School for Advanced Studies
 3. ICTP  International Center for Theoretical Physics [Trieste]

Evidence of spintemperature in dynamic nuclear polarization: an exact computation of the EPR spectrum
Filippo Caracciolo ^{1} Marta Filibian ^{1} Pietro Carretta ^{1} Alberto Rosso ^{2} Andrea De Luca ^{2}
PCCP : Physical chemistry chemical physics, Royal Society of Chemistry, 2016, 18, pp.25655
In a dynamic nuclear polarization (DNP) procedure, the compound is driven outofequilibrium by microwave irradiation of the dipolar electron spins of the radical. The main outcome of this protocol is the huge polarization enhancement for nuclear spins. In this paper, we focus on the steadystate polarization of the electron spins, which is experimentally accessible via ELDOR techniques. By varying the radical concentration, two scenarios emerge: for dilute samples, the irradiated ELDOR spectrum displays the narrow holeburning profile predicted by Bloch equations; for higher concentrations, the ELDOR spectrum is completely reorganized according to the spintemperature description. We discuss our results in relation with recent EPR experiments and, in particular, we analyze the dependence on the microwave intensity.
 1. CNISM  Dipartimento di Fisica and Unità
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Exact distributions of cover times for $N$ independent random walkers in one dimension
Satya N. Majumdar ^{1} Sanjib Sabhapandit ^{2} Gregory Schehr ^{1}
Physical Review E , American Physical Society (APS), 2016, 94 (6), pp.062131
We study the probability density function (PDF) of the cover time $t_c$ of a finite interval of size $L$, by $N$ independent onedimensional Brownian motions, each with diffusion constant $D$. The cover time $t_c$ is the minimum time needed such that each point of the entire interval is visited by at least one of the $N$ walkers. We derive exact results for the full PDF of $t_c$ for arbitrary $N \geq 1$, for both reflecting and periodic boundary conditions. The PDFs depend explicitly on $N$ and on the boundary conditions. In the limit of large $N$, we show that $t_c$ approaches its average value $\langle t_c \rangle \approx L^2/(16\, D \, \ln N)$, with fluctuations vanishing as $1/(\ln N)^2$. We also compute the centered and scaled limiting distributions for large $N$ for both boundary conditions and show that they are given by nontrivial $N$independent scaling functions.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Raman Research Institute

Exact extreme value statistics at mixed order transitions
Amir Bar ^{1} Satya N. Majumdar ^{2} Gregory Schehr ^{2} David Mukamel ^{1}
Physical Review E , American Physical Society (APS), 2016, 93, pp.052130
We study extreme value statistics (EVS) for spatially extended models exhibiting mixed order phase transitions (MOT). These are phase transitions which exhibit features common to both first order (discontinuity of the order parameter) and second order (diverging correlation length) transitions. We consider here the truncated inverse distance squared Ising (TIDSI) model which is a prototypical model exhibiting MOT, and study analytically the extreme value statistics of the domain lengths. The lengths of the domains are identically distributed random variables except for the global constraint that their sum equals the total system size $L$. In addition, the number of such domains is also a fluctuating variable, and not fixed. In the paramagnetic phase, we show that the distribution of the largest domain length $l_{\max}$ converges, in the large $L$ limit, to a Gumbel distribution. However, at the critical point (for a certain range of parameters) and in the ferromagnetic phase, we show that the fluctuations of $l_{\max}$ are governed by novel distributions which we compute exactly. Our main analytical results are verified by numerical simulations.
 1. Weizmann Institute
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Exact gap statistics for the random average process on a ring with a tracer
Julien Cividini ^{1} Anupam Kundu ^{2, 3, 1} Satya N. Majumdar ^{3} David Mukamel ^{1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.085002
We study statistics of the gaps in Random Average Process (RAP) on a ring with particles hopping symmetrically, except one tracer particle which could be driven. These particles hop either to the left or to the right by a random fraction $\eta$ of the space available till next particle in the respective directions. The random fraction $\eta \in [0,~1)$ is chosen from a distribution $R(\eta)$. For nondriven tracer, when $R(\eta)$ satisfies a necessary and sufficient condition, the stationary joint distribution of the gaps between successive particles takes an universal form that is factorized except for a global constraint. Some interesting explicit forms of $R(\eta)$ are found which satisfy this condition. In case of driven tracer, the system reaches a currentcarrying steady state where such factorization does not hold. Analytical progress has been made in the thermodynamic limit, where we computed the single site mass distribution inside the bulk. We have also computed the two point gapgap correlation exactly in that limit. Numerical simulations support our analytical results.
 1. Weizmann Institute
 2. International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Exact ShortTime Height Distribution in the OneDimensional KardarParisiZhang Equation and Edge Fermions at High Temperature
Pierre Le Doussal ^{1} Satya N. Majumdar ^{2} Alberto Rosso ^{2} Grégory Schehr ^{2}
Physical Review Letters, American Physical Society, 2016, 117 (7), pp.070403
 1. LPTENS  Laboratoire de Physique Théorique de l'ENS
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Exact statistics of record increments of random walks and L\’evy flights
Claude Godreche ^{1} Satya N. Majumdar ^{2} Gregory Schehr ^{2}
Physical Review Letters, American Physical Society, 2016, 117, pp.010601
We study the statistics of increments in record values in a time series $\{x_0=0,x_1, x_2, \ldots, x_n\}$ generated by the positions of a random walk (discrete time, continuous space) of duration $n$ steps. For arbitrary jump length distribution, including L\'evy flights, we show that the distribution of the record increment becomes stationary, i.e., independent of $n$ for large $n$, and compute it explicitly for a wide class of jump distributions. In addition, we compute exactly the probability $Q(n)$ that the record increments decrease monotonically up to step $n$. Remarkably, $Q(n)$ is universal (i..e., independent of the jump distribution) for each $n$, decaying as $Q(n) \sim {\cal A}/\sqrt{n}$ for large $n$, with a universal amplitude ${\cal A} = e/\sqrt{\pi} = 1.53362\ldots$.
 1. IPHT  Institut de Physique Théorique  UMR CNRS 3681
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Extreme value statistics of 2d Gaussian Free Field: effect of finite domains
Xiangyu Cao ^{1} Alberto Rosso ^{1} Raoul Santachiara ^{1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.02LT02
We study minima statistics of the 2d Gaussian Free Field on circles in the unit disk with Dirichlet boundary condition. Free energy distributions of the associated Random Energy models are exactly calculated in the high temperature phase, and shown to satisfy the duality property, which enables us to predict the minima distribution by assuming the freezing scenario. Numerical tests are provided. Related questions concerning the GFF on a sphere are also considered.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Fast electronic resistance switching involving hidden charge density wave states
I. Vaskivskyi ^{1, 2} I. A. Mihailovic ^{2, 1} S. Brazovskii ^{3, 4} J. Gospodaric ^{2} T. Mertelj ^{2} D. Svetin ^{2} P. Sutar ^{2} D. Mihailovic ^{5, 2, 1}
Nature Communications, Nature Publishing Group, 2016, 7, pp.11442
 1. University of Ljubljana
 2. Department of Complex Matter
 3. MISIS  National University of Science and Technology
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 5. Jozef Stefan International Postgraduate School [Ljubljana, Slovenia]

Fast equilibrium switch of a micro mechanical oscillator
Anne Le Cunuder ^{1} Ignacio Martinez ^{1} Artyom Petrosyan ^{1} David GuéryOdelin ^{2} Emmanuel Trizac ^{3} Sergio Ciliberto ^{1}
Applied Physics, SpringerVerlag, 2016, Applied Physics Letters 109, pp.113502
We demonstrate an accurate method to control the motion of a micromechanical oscillator in contact with a thermal bath. The experiment is carried out on the cantilever tip of an Atomic Force Microscope (AFM). Applying an appropriate time dependent external force, we decrease the time necessary to reach equilibrium by two orders of magnitude compared to the intrinsic equilibration time. Finally, we analyze the energetic cost of such a fast equilibration, by measuring with kBT accuracy the energy exchanges along the process.
 1. PhysENS  Laboratoire de Physique de l'ENS Lyon
 2. Atomes Froids (LCAR)
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Fiber networks amplify active stress
Pierre Ronceray ^{1} Chase Broedersz ^{2, 3} Martin Lenz ^{1}
Proceedings of the National Academy of Sciences of the United States of America , National Academy of Sciences, 2016, 113, pp.2827
Largescale force generation is essential for biological functions such as cell motility, embryonic development, and muscle contraction. In these processes, forces generated at the molecular level by motor proteins are transmitted by disordered fiber networks, resulting in largescale active stresses. While these fiber networks are well characterized macroscopically, this stress generation by microscopic active units is not well understood. Here we theoretically study force transmission in these networks, and find that local active forces are rectified towards isotropic contraction and strongly amplified as fibers collectively buckle in the vicinity of the active units. This stress amplification is reinforced by the networks' disordered nature, but saturates for high densities of active units. Our predictions are quantitatively consistent with experiments on reconstituted tissues and actomyosin networks, and shed light on the role of the network microstructure in shaping active stresses in cells and tissue.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Arnold Sommerfeld Center for Theoretical Physics
 3. LewisSigler Institute for Integrative Genomics

Finite N corrections to the limiting distribution of the smallest eigenvalue of Wishart complex matrices
Anthony Perret ^{1} Gregory Schehr ^{1}
Random Matrices. Theory and Applications, 2016, 5, pp.1650001
We study the probability distribution function (PDF) of the smallest eigenvalue of LaguerreWishart matrices $W = X^\dagger X$ where $X$ is a random $M \times N$ ($M \geq N$) matrix, with complex Gaussian independent entries. We compute this PDF in terms of semiclassical orthogonal polynomials, which are deformations of Laguerre polynomials. By analyzing these polynomials, and their associated recurrence relations, in the limit of large $N$, large $M$ with $M/N \to 1$  i.e. for quasisquare large matrices $X$  we show that this PDF, in the hard edge limit, can be expressed in terms of the solution of a Painlev\'e III equation, as found by Tracy and Widom, using Fredholm operators techniques. Furthermore, our method allows us to compute explicitly the first $1/N$ corrections to this limiting distribution at the hard edge. Our computations confirm a recent conjecture by Edelman, Guionnet and P\'ech\'e. We also study the soft edge limit, when $MN \sim {\cal O}(N)$, for which we conjecture the form of the first correction to the limiting distribution of the smallest eigenvalue.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Finitetemperature effects on interacting bosonic onedimensional systems in disordered lattices
Lorenzo Gori ^{1} Thomas Barthel ^{2, 3} Avinash Kumar ^{1} Eleonora Lucioni ^{4, 1} Luca Tanzi ^{1} Massimo Inguscio ^{1, 4} Giovanni Modugno ^{1, 4} Thierry Giamarchi ^{5} Chiara D'Errico ^{1, 4} Guillaume Roux ^{3}
Physical Review A, American Physical Society, 2016, 93, pp.033650
We analyze the finitetemperature effects on the phase diagram describing the insulating properties of interacting 1D bosons in a quasiperiodic lattice. We examine thermal effects by comparing experimental results to exact diagonalization for smallsized systems and to densitymatrix renormalization group (DMRG) computations. At weak interactions, we find short thermal correlation lengths, indicating a substantial impact of temperature on the system coherence. Conversely, at strong interactions, the obtained thermal correlation lengths are significantly larger than the localization length, and the quantum nature of the T=0 Bose glass phase is preserved up to a crossover temperature that depends on the disorder strength. Furthermore, in the absence of disorder, we show how quasiexact finiteT DMRG computations, compared to experimental results, can be employed to estimate the temperature, which is not directly accessible in the experiment.
 1. European Laboratory for Nonlinear Spectroscopy (LENS)
 2. Duke university [Durham]
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. CNRIFAC, Sesto Fiorentino
 5. DPMC  Département de Physique de la Matière Condensée

Finitetemperature fluid–insulator transition of strongly interacting 1D disordered bosons
Vincent P. Michal ^{1} Igor L. Aleiner ^{2} Boris L. Altshuler ^{3, 2} Georgy V. Shlyapnikov ^{4, 5, 1, 3}
Proceedings of the National Academy of Sciences of the United States of America , National Academy of Sciences, 2016, 113 (31), pp.E4455  E4459
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Columbia University [New York]
 3. Wuhan Institute of Physics and Mathematics
 4. VAN DER WAALSZEEMAN INSTITUTE  University of Amsterdam Van der WaalsZeeman Institute
 5. Russian Quantum Center

Formation of exciton rings and localized bright spots in coupled semiconductor quantum wells
S. V. Andreev ^{1, 2, 3, *}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 94 (16), pp.165308 (16). <10.1103/PhysRevB.94.165308>
We consider indirect excitons generated at the ringshaped boundaries between electronand holerich regions in semiconductor quantum wells (QW's). We show theoretically that the inplane translational motion of the excitons is confined in the radial direction. The confinement potential results from the electrostatic interaction of the exciton dipole moment with the inplane electric field induced at the boundary by the macroscopic charge separation. Our results directly apply to the external ring and the localized bright spots (LBS) observed in the photoluminescense (PL) pattern of indirect excitons.
 1. ITMO  National Research University of Information Technologies, Mechanics and Optics [St. Petersburg]
 2. LOMA  Laboratoire Ondes et Matière d'Aquitaine
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Fourterminal resistances in mesoscopic networks of metallic wires: Weak localisation and correlations
Christophe Texier ^{1} Gilles Montambaux ^{2}
Physica E: Lowdimensional Systems and Nanostructures, Elsevier, 2016, 75, pp.33
We consider the electronic transport in multiterminal mesoscopic networks of weakly disordered metallic wires. After a brief description of the classical transport, we analyze the weak localisation (WL) correction to the fourterminal resistances, which involves an integration of the Cooperon over the wires with proper weights. We provide an interpretation of these weights in terms of classical transport properties. We illustrate the formalism on examples and show that weak localisation to fourterminal conductances may become large in some situations. In a second part, we study the correlations of fourterminal resistances and show that integration of Diffuson and Cooperon inside the network involves the same weights as the WL. The formulae are applied to multiconnected wire geometries.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPS  Laboratoire de Physique des Solides

From liquid structure to configurational entropy: introducing structural covariance
Pierre Ronceray ^{1} Peter Harrowell ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, 2016 (8), pp.084002
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Faculty of Sciences

Fully developed isotropic turbulence: nonperturbative renormalization group formalism and fixed point solution
Léonie Canet ^{1} Bertrand Delamotte ^{2, 3} Nicolás Wschebor ^{2, 3}
Phys.Rev., 2016, E93 (6), pp.063101. 〈10.1103/PhysRevE.93.063101〉
We investigate the regime of fully developed homogeneous and isotropic turbulence of the NavierStokes (NS) equation in the presence of a stochastic forcing, using the nonperturbative (functional) renormalization group (NPRG). Within a simple approximation based on symmetries, we obtain the fixedpoint solution of the NPRG flow equations that corresponds to fully developed turbulence both in d=2 and 3 dimensions. Deviations to the dimensional scalings (Kolmogorov in d=3 or KraichnanBatchelor in d=2) are found for the twopoint functions. To further analyze these deviations, we derive exact flow equations in the large wavenumber limit, and show that the fixed point does not entail the usual scale invariance, thereby identifying the mechanism for the emergence of intermittency within the NPRG framework. The purpose of this work is to provide a detailed basis for NPRG studies of NS turbulence; the determination of the ensuing intermittency exponents is left for future work.
 1. LPMMC  Laboratoire de physique et modélisation des milieux condensés
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée

Identifying relevant positions in proteins by Critical Variable Selection
Silvia Grigolon ^{1} Silvio Franz ^{1} Matteo Marsili ^{2}
Molecular BioSystems, Royal Society of Chemistry, 2016, 12, pp.2147
Evolution in its course found a variety of solutions to the same optimisation problem. The advent of highthroughput genomic sequencing has made available extensive data from which, in principle, one can infer the underlying structure on which biological functions rely. In this paper, we present a new method aimed at extracting sites encoding structural and func tional properties from a set of protein primary sequences, namely a Multiple Sequence Alignment. The method, called Critical Variable Selection, is based on the idea that subsets of relevant sites cor respond to subsequences that occur with a particularly broad frequency distribution in the dataset. By applying this algorithm to in silico sequences, to the Response Regulator Receiver and to the Voltage Sensor Domain of Ion Channels, we show that this procedure recovers not only information encoded in single site statistics and pairwise correlations but it also captures dependencies going beyond pairwise correlations. The method proposed here is complementary to Statistical Coupling Analysis, in that the most relevant sites predicted by the two methods markedly differ. We find robust and consistent results for datasets as small as few hundred sequences, that reveal a hidden hierarchy of sites that is consistent with present knowledge on biologically relevant sites and evo lutionary dynamics. This suggests that Critical Variable Selection is able to identify in a Multiple Sequence Alignment a core of sites encoding functional and structural information.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. ICTP  International Center for Theoretical Physics [Trieste]

Information processing using threequbit and qubitqutrit encodings of noncomposite quantum systems
A. A. Popov ^{1} E. O. Kiktenko ^{1} A. K. Fedorov ^{2, 3} V. I. Man'Ko ^{4, 5}
Journal of Russian Laser Research, Springer Verlag, 2016, 37, pp.581
We study quantum information properties of a sevenlevel system realized by a particle in an onedimensional squarewell trap. Features of encodings of sevenlevel systems in a form of threequbit or qubitqutrit systems are discussed. We use the threequbit encoding of the system in order to investigate subadditivity and strong subadditivity conditions for the thermal state of the particle. The qubitqutrit encoding is employed to suggest a single qudit algorithm for calculation of parity of a bit string. Obtained results indicate on the potential resource of multilevel systems for realization of quantum information processing.
 1. Bauman Moscow State Technical University
 2. Russian Quantum Center
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. MIPT  Moscow Institute of Physics and Technology [Moscow]
 5. P. N. Lebedev Physical Institute of the Russian Academy of Sciences

Itinerant ferromagnetism in 1D twocomponent Fermi gases
Yuzhu Jiang ^{1} D. V. Kurlov ^{2} XiWen Guan ^{1, 3} F. Schreck ^{2} G. V. Shlyapnikov ^{4, 1, 2, 5}
Physical Review A, American Physical Society, 2016, 94, pp.011601
We study a onedimensional twocomponent atomic Fermi gas with an infinite intercomponent contact repulsion. It is found that adding an attractive resonant oddwave interaction breaking the rotational symmetry one can make the ground state ferromagnetic. A promising system for the observation of this itinerant ferromagnetic state is a 1D gas of $^{40}$K atoms, where 3D $s$wave and $p$wave Feshbach resonances are very close to each other and the 1D confinement significantly reduces the inelastic decay.
 1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071 China
 2. VAN DER WAALSZEEMAN INSTITUTE  University of Amsterdam Van der WaalsZeeman Institute
 3. Department of Physics, Australian National University
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 5. Russian Quantum Center

Joint minmax distribution and EdwardsAnderson’s order parameter of the circular 1/fnoise model
Xiangyu Cao ^{1} Pierre Le Doussal ^{2}
EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2016, 114 (4), pp.40003
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS

L’entraînement cognitivoperceptif basé sur la vidéo et ses modes d’instructions – Archive ouverte HAL
Nicolas Milazzo ^{1} Marjorie Bernier ^{2} E. RosnetD. FarrowJ.F. Fournier
Nicolas Milazzo, Marjorie Bernier, E. Rosnet, D. Farrow, J.F. Fournier. L’entraînement cognitivoperceptif basé sur la vidéo et ses modes d’instructions. Psychologie Française, Elsevier Masson, 2016, 61 (4), pp.273289. ⟨10.1016/j.psfr.2015.07.004⟩. ⟨hal02512758⟩
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. CREAD EA 3875  Centre de Recherche sur l'Education, les apprentissages et la didactique

Large deviations for the height in 1D KardarParisiZhang growth at late times
Pierre Le Doussal ^{1} Satya N. Majumdar ^{2} Gregory Schehr ^{2}
EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2016, 113, pp.60004
We study the atypically large deviations of the height $H \sim {{\cal O}}(t)$ at the origin at late times in $1+1$dimensional growth models belonging to the KardarParisiZhang (KPZ) universality class. We present exact results for the rate functions for the discrete single step growth model, as well as for the continuum KPZ equation in a droplet geometry. Based on our exact calculation of the rate functions we argue that models in the KPZ class undergo a third order phase transition from a strong coupling to a weak coupling phase, at late times.
 1. LPTENS  Laboratoire de Physique Théorique de l'ENS
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Lifetime of Feshbach dimers in a FermiFermi mixture of $^6$Li and $^{40}$K
Michael Jag ^{1} Marko Cetina ^{2} Rianne S. Lous ^{1} Rudolf Grimm ^{1} Jesper Levinsen ^{3, 4} Dmitry S. Petrov ^{5}
Physical Review A, American Physical Society, 2016, 94 (6), pp.062706
 1. Institut für Experimentalphysik [Innsbruck]
 2. Institut für Quantenoptik und Quanteninformation
 3. TCM Group, Cavendish Laboratory
 4. Aarhus Institute of Advanced Studies
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Meanfield beyond meanfield: the single particle view for moderately to strongly coupled charged fluids
L. Samaj ^{1} A. P. Dos Santos ^{2} Y. Levin ^{2} E. Trizac ^{3}
Soft Matter, Royal Society of Chemistry, 2016, 12, pp.8768
 1. INSTITUTE OF PHYSICS  SLOVAK ACADEMY OF SCIENCES Institute of Physics Dubraska cesta 9, 84228 Bratislava, Slovaquie
 2. UFRGS  Universidade Federal do Rio Grande do Sul [Porto Alegre]
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Membrane fission by dynamin: what we know and what we need to know
Bruno Antonny ^{1} Christopher BurdPietro De Camilli ^{2} Elizabeth ChenOliver DaumkeKatja FaelberMarijn FordVadim A FrolovAdam FrostJenny E HinshawTom KirchhausenMichael M KozlovMartin Lenz ^{3} Harry H LowHarvey McmahonChristien Merrifield ^{4} Thomas D PollardPhillip J RobinsonAurélien Roux ^{5} Sandra Schmid
EMBO Journal, EMBO Press, 2016, 35 (21), pp.2270  2284. 〈10.15252/embj.201694613〉
 1. IPMC  Institut de pharmacologie moléculaire et cellulaire
 2. Department of Cell Biology [New Haven]
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Institute for Integrative Biology of the Cell
 5. PCC  PhysicoChimieCurie

Microscopic origin of selfsimilarity in granular blast waves
M. Barbier ^{1} D. Villamaina ^{2} E. Trizac ^{3}
Physics of Fluids, American Institute of Physics, 2016, 28 (8), pp.083302
 1. Department of Ecology and Evolutionary Biology [Princeton]
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Native ultrametricity of sparse random ensembles
V. Avetisov ^{1, 2} P. L. Krapivsky ^{3} S. Nechaev ^{4, 5}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.035101
We investigate the eigenvalue density in ensembles of large sparse Bernoulli random matrices. We demonstrate that the fraction of linear subgraphs just below the percolation threshold is about 95\% of all finite subgraphs, and the distribution of linear chains is purely exponential. We analyze in detail the spectral density of ensembles of linear subgraphs, discuss its ultrametric nature and show that near the spectrum boundary, the tail of the spectral density exhibits a Lifshitz singularity typical for Anderson localization. We also discuss an intriguing connection of the spectral density to the Dedekind $\eta$function. We conjecture that ultrametricity is inherit to complex systems with extremal sparse statistics and argue that a numbertheoretic ultrametricity emerges in any rareevent statistics.
 1. Department of Applied Mathematics
 2. The Semenov Institute of Chemical Physics
 3. Boston University, Boston, Massachusetts, USA
 4. P. N. Lebedev Physical Institute [Moscow]
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Non Relativistic Limit of Integrable QFT and LiebLiniger Models
Alvise Bastianello ^{1} Andrea De Luca ^{2} Giuseppe Mussardo ^{3}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, 2016 (12), pp.123104
In this paper we study a suitable limit of integrable QFT with the aim to identify continuous nonrelativistic integrable models with local interactions. This limit amounts to sending to infinity the speed of light c but simultaneously adjusting the coupling constant g of the quantum field theories in such a way to keep finite the energies of the various excitations. The QFT considered here are Toda Field Theories and the O(N) nonlinear sigma model. In both cases the resulting nonrelativistic integrable models consist only of LiebLiniger models, which are fully decoupled for the Toda theories while symmetrically coupled for the O(N) model. These examples provide explicit evidence of the universality and ubiquity of the LiebLiniger models and, at the same time, suggest that these models may exhaust the list of possible nonrelativistic integrable theories of bosonic particles with local interactions.
 1. SISSA / ISAS  Scuola Internazionale Superiore di Studi Avanzati / International School for Advanced Studies
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. ICTP  International Center for Theoretical Physics [Trieste]

Noninteracting fermions at finite temperature in a $d$dimensional trap: universal correlations
David S. Dean ^{1} Pierre Le Doussal ^{2} Satya N. Majumdar ^{3} Gregory Schehr ^{3} Pierre Le Doussal ^{2}
Physical Review A, American Physical Society, 2016, 94 (6), pp.063622
We study a system of $N$ noninteracting spinless fermions trapped in a confining potential, in arbitrary dimensions $d$ and arbitrary temperature $T$. The presence of the trap introduces an edge where the average density of fermions vanishes. Far from the edge, near the center of the trap (the so called "bulk regime"), physical properties of the fermions have traditionally been understood using the Local Density Approximation. However, this approximation drastically fails near the edge where the density vanishes. In this paper we show that, even near the edge, novel universal properties emerge, independently of the details of the confining potential. We show that for large $N$, these fermions in a confining trap, in arbitrary dimensions and at finite temperature, form a determinantal point process. As a result, any $n$point correlation function can be expressed as an $n \times n$ determinant whose entry is called the kernel. Near the edge, we derive the large $N$ scaling form of the kernels. In $d=1$ and $T=0$, this reduces to the so called Airy kernel, that appears in the Gaussian Unitary Ensemble (GUE) of random matrix theory. In $d=1$ and $T>0$ we show a remarkable connection between our kernel and the one appearing in the $1+1$dimensional KardarParisiZhang equation at finite time. Consequently our result provides a finite $T$ generalization of the TracyWidom distribution, that describes the fluctuations of the rightmost fermion at $T=0$. In $d>1$ and $T \geq 0$, while the connection to GUE no longer holds, the process is still determinantal whose analysis provides a new class of kernels, generalizing the $1d$ Airy kernel at $T=0$ obtained in random matrix theory. Some of our finite temperature results should be testable in presentday cold atom experiments, most notably our detailed predictions for the temperature dependence of the fluctuations near the edge.
 1. LOMA  Laboratoire Ondes et Matière d'Aquitaine
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Nonergodic Phases in Strongly Disordered Random Regular Graphs
B. l. Altshuler ^{1} E. Cuevas ^{2} L. b. Ioffe ^{3, 4} V. e. Kravtsov ^{5, 4}
Physical Review Letters, American Physical Society, 2016, 117 (15), pp.156601
 1. Columbia University [New York]
 2. University of Murcia
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. LANDAU INSTITUTE  Landau Institute for Theoretical Physics
 5. ICTP  International Center for Theoretical Physics [Trieste]

Noninteracting fermions at finite temperature in a d dimensional trap: Universal correlations
David S. Dean ^{1} Pierre Le Doussal ^{2} Satya N. Majumdar ^{3} Grégory Schehr ^{3}
Physical Review A, American Physical Society, 2016, 94 (6), pp.063622 (141). <10.1103/PhysRevA.94.063622>
We study a system of $N$ noninteracting spinless fermions trapped in a confining potential, in arbitrary dimensions $d$ and arbitrary temperature $T$. The presence of the trap introduces an edge where the average density of fermions vanishes. Far from the edge, near the center of the trap (the so called "bulk regime"), physical properties of the fermions have traditionally been understood using the Local Density Approximation. However, this approximation drastically fails near the edge where the density vanishes. In this paper we show that, even near the edge, novel universal properties emerge, independently of the details of the confining potential. We show that for large $N$, these fermions in a confining trap, in arbitrary dimensions and at finite temperature, form a determinantal point process. As a result, any $n$point correlation function can be expressed as an $n \times n$ determinant whose entry is called the kernel. Near the edge, we derive the large $N$ scaling form of the kernels. In $d=1$ and $T=0$, this reduces to the so called Airy kernel, that appears in the Gaussian Unitary Ensemble (GUE) of random matrix theory. In $d=1$ and $T>0$ we show a remarkable connection between our kernel and the one appearing in the $1+1$dimensional KardarParisiZhang equation at finite time. Consequently our result provides a finite $T$ generalization of the TracyWidom distribution, that describes the fluctuations of the rightmost fermion at $T=0$. In $d>1$ and $T \geq 0$, while the connection to GUE no longer holds, the process is still determinantal whose analysis provides a new class of kernels, generalizing the $1d$ Airy kernel at $T=0$ obtained in random matrix theory. Some of our finite temperature results should be testable in presentday cold atom experiments, most notably our detailed predictions for the temperature dependence of the fluctuations near the edge.
 1. LOMA  Laboratoire Ondes et Matière d'Aquitaine
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Nonlinear waves in coherently coupled BoseEinstein condensates
T. Congy ^{1} A. Kamchatnov ^{2} N. Pavloff ^{1}
Physical Review A, American Physical Society, 2016, 93, pp.043613
We consider a quasionedimensional twocomponent BoseEinstein condensate subject to a coherent coupling between its components, such as realized in spinorbit coupled condensates. We study how nonlinearity modifies the dynamics of the elementary excitations. The spectrum has two branches which are affected in different ways. The upper branch experiences a modulational instability which is stabilized by a long waveshort wave resonance with the lower branch. The lower branch is stable. In the limit of weak nonlinearity and small dispersion it is described by a Kortewegde Vries equation or by the Gardner equation, depending on the value of the parameters of the system.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Institute of Spectroscopy

Novel $p$wave superfluids of fermionic polar molecules
A. K. Fedorov ^{1, 2} S. I. Matveenko ^{3, 2} V. I. Yudson ^{4, 1} G. V. Shlyapnikov ^{5, 2, 1, 6}
Scientific Reports, Nature Publishing Group, 2016, 6, pp.27448
We show that recently suggested subwavelength lattices offer remarkable prospects for the observation of novel superfluids of fermionic polar molecules. It becomes realistic to obtain a topological $p$wave superfluid of microwavedressed polar molecules in 2D lattices at temperatures of the order of tens of nanokelvins, which is promising for topologically protected quantum information processing. Another foreseen novel phase is an interlayer $p$wave superfluid of polar molecules in a bilayer geometry.
 1. Russian Quantum Center
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Landau Institute for Theoretical Physics
 4. Institute of Spectroscopy
 5. Wuhan Institute of Physics and Mathematics
 6. Van der Waals  Zeeman Institute

Nuclear Magnetic Resonance studies of DNPready trehalose obtained by solid state mechanochemical amorphization
Marta Filibian ^{1} Elena Elisei ^{2, 3} Sonia Colombo Serra ^{4} Alberto Rosso ^{5} Fabio Tedoldi ^{4} Attilio Cesàro ^{3, 6} Pietro Carretta ^{1}
Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2016, 18, pp.16912
 1. CNISM  Dipartimento di Fisica and Unità
 2. UMET  Unité Matériaux et Transformations
 3. Department of Chemical and Pharmaceutical Sciences
 4. Centro Ricerche Bracco
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. SINCROTRONE TRIESTE  Sincrotrone Trieste SCpA

Number statistics for β ensembles of random matrices: Applications to trapped fermions at zero temperature
Ricardo Marino ^{1} Satya N. Majumdar ^{2} Grégory Schehr ^{2} Pierpaolo Vivo ^{3}
Physical Review E , American Physical Society (APS), 2016, 94 (3), pp.032115
 1. WIS  Weizmann Institute of Science
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. King's College London

Occupation time statistics of the random acceleration model
Hermann Joel Ouandji Boutcheng ^{1, 2} Thomas Bouetou Bouetou ^{3, 1} Theodore W. Burkhardt ^{4} Alberto Rosso ^{5} Andrea Zoia ^{6} Kofane Timoleon Crepin ^{2, 1}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, pp.053213
The random acceleration model is one of the simplest nonMarkovian stochastic systems and has been widely studied in connection with applications in physics and mathematics. However, the occupation time and related properties are nontrivial and not yet completely understood. In this paper we consider the occupation time $T_+$ of the onedimensional random acceleration model on the positive halfaxis. We calculate the first two moments of $T_+$ analytically and also study the statistics of $T_+$ with Monte Carlo simulations. One goal of our work was to ascertain whether the occupation time $T_+$ and the time $T_m$ at which the maximum of the process is attained are statistically equivalent. For regular Brownian motion the distributions of $T_+$ and $T_m$ coincide and are given by L\'evy's arcsine law. We show that for randomly accelerated motion the distributions of $T_+$ and $T_m$ are quite similar but not identical. This conclusion follows from the exact results for the moments of the distributions and is also consistent with our Monte Carlo simulations.
 1. CETIC asbl  Centre d’Excellence en Technologies de l’Information et de la Communication
 2. University of Yaoundé [Cameroun]
 3. ENSP  Ecole Nationale Supérieure Polytechnique [Yaoundé]
 4. Temple University [Philadelphia]
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. CEADEN  CEADirection de l'Energie Nucléaire

On determinant representations of scalar products and form factors in the SoV approach: the XXX case
Nikolai Kitanine ^{1} J. M. Maillet ^{2} G. Niccoli ^{2} Véronique Terras ^{3}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49 (10), pp.104002. <10.1088/17518113/49/10/104002 >
In the present article we study the form factors of quantum integrable lattice models solvable by the separation of variables (SoVs) method. It was recently shown that these models admit universal determinant representations for the scalar products of the socalled separate states (a class which includes in particular all the eigenstates of the transfer matrix). These results permit to obtain simple expressions for the matrix elements of local operators (form factors). However, these representations have been obtained up to now only for the completely inhomogeneous versions of the lattice models considered. In this article we give a simple algebraic procedure to rewrite the scalar products (and hence the form factors) for the SoV related models as Izergin or Slavnov type determinants. This new form leads to simple expressions for the form factors in the homogeneous and thermodynamic limits. To make the presentation of our method clear, we have chosen to explain it first for the simple case of the XXX Heisenberg chain with antiperiodic boundary conditions. We would nevertheless like to stress that the approach presented in this article applies as well to a wide range of models solved in the SoV framework.
 1. IMB  Institut de Mathématiques de Bourgogne [Dijon]
 2. PhysENS  Laboratoire de Physique de l'ENS Lyon
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

On the algebraic area of lattice walks and the Hofstadter model
Stephane Ouvry ^{1} Stephan Wagner ^{2} Shuang Wu ^{1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.495205
We consider the generating function of the algebraic area of lattice walks, evaluated at a root of unity, and its relation to the Hofstadter model. In particular, we obtain an expression for the generating function of the nth moments of the Hofstadter Hamiltonian in terms of a complete elliptic integral, evaluated at a rational function. This in turn gives us both exact and asymptotic formulas for these moments.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Department of Mathematics [Stellenbosch]

On the Gap and Time Interval between the First Two Maxima of Long Continuous Time Random Walks
Philippe Mounaix ^{1} Gregory Schehr ^{2} Satya N. Majumdar ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Publishing, 2016, pp.013303
We consider a onedimensional continuous time random walk (CTRW) on a fixed time interval $T$ where at each time step the walker waits a random time $\tau$, before performing a jump drawn from a symmetric continuous probability distribution function (PDF) $f(\eta)$, of L\'evy index $0 < \mu \leq 2$. Our study includes the case where the waiting time PDF $\Psi(\tau)$ has a power law tail, $\Psi(\tau) \propto \tau^{1  \gamma}$, with $0< \gamma < 1$, such that the average time between two consecutive jumps is infinite. The random motion is subdiffusive if $\gamma < \mu/2$ (and superdiffusive if $\gamma > \mu/2$). We investigate the joint PDF of the gap $g$ between the first two highest positions of the CTRW and the time $t$ separating these two maxima. We show that this PDF reaches a stationary limiting joint distribution $p(g,t)$ in the limit of long CTRW, $T \to \infty$. Our exact analytical results show a very rich behavior of this joint PDF in the $(\gamma, \mu)$ plane, which we study in great detail. Our main results are verified by numerical simulations. This work provides a non trivial extension to CTRWs of the recent study in the discrete time setting by Majumdar et al. (J. Stat. Mech. P09013, 2014).
 1. CPHT  Centre de Physique Théorique [Palaiseau]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

One step replica symmetry breaking and extreme order statistics of logarithmic REMs
Xiangyu Cao ^{1} Yan V. Fyodorov ^{2} Pierre Le Doussal ^{3}
SciPost Physics, 2016, 1, pp.011
Building upon the onestep replica symmetry breaking formalism, duly understood and ramified, we show that the sequence of ordered extreme values of a general class of Euclideanspace logarithmically correlated random energy models (logREMs) behave in the thermodynamic limit as a randomly shifted decorated exponential Poisson point process. The distribution of the random shift is determined solely by the largedistance ("infrared", IR) limit of the model, and is equal to the free energy distribution at the critical temperature up to a translation. the decoration process is determined solely by the smalldistance ("ultraviolet", UV) limit, in terms of the biased minimal process. Our approach provides connections of the replica framework to results in the probability literature and sheds further light on the freezing/duality conjecture which was the source of many previous results for logREMs. In this way we derive the general and explicit formulae for the joint probability density of depths of the first and second minima (as well its higherorder generalizations) in terms of modelspecific contributions from UV as well as IR limits. In particular, we show that the second min statistics is largely independent of details of UV data, whose influence is seen only through the mean value of the gap. For a given logcorrelated field this parameter can be evaluated numerically, and we provide several numerical tests of our theory using the circular model of $1/f$noise.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. School of Mathematical Sciences [London]
 3. LPTENS  Laboratoire de Physique Théorique de l'ENS

Opticallatticeassisted magnetic phase transition in a spinorbitcoupled BoseEinstein condensate
Giovanni I. Martone ^{1, 2, 3, 4} Tomoki Ozawa ^{4} Chunlei Qu ^{4} Sandro Stringari ^{4}
Physical Review A, American Physical Society, 2016, 94 (4), pp.043629
 1. Università degli studi di Bari
 2. INFN, Sezione di Bari  Istituto Nazionale di Fisica Nucleare, Sezione di Bari
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. INOCNR BEC  Università di Trento

Optomechanical manybody cooling using frustration
Thomás Fogarty ^{1} Haggai Landa ^{2} Cecilia Cormick ^{3} Giovanna Morigi ^{1}
Physical Review A, American Physical Society, 2016, 94 (2), pp.023844
 1. Universität des Saarlandes [Saarbrücken]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. IFEG  Instituto de Fisica Enrique Gaviola

Origin of emission from squareshaped organic microlasers
S. Bittner ^{1, 2} C. Lafargue ^{2} I. Gozhyk ^{2, 3} N. Djellali ^{2} L. Milliet ^{2} D. T. HickoxYoung ^{2} C. Ulysse ^{4} D. Bouche ^{5} R. Dubertrand ^{6} E. Bogomolny ^{7} J. Zyss ^{2} M. Lebental ^{2}
EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2016, 113, pp.54002
The emission from open cavities with nonintegrable features remains a challenging problem of practical as well as fundamental relevance. Squareshaped dielectric microcavities provide a favorable case study with generic implications for other polygonal resonators. We report on a joint experimental and theoretical study of squareshaped organic microlasers exhibiting a farfield emission that is strongly concentrated in the directions parallel to the side walls of the cavity. A semiclassical model for the farfield distributions is developed that is in agreement with even fine features of the experimental findings. Comparison of the model calculations with the experimental data allows the precise identification of the lasing modes and their emission mechanisms, providing strong support for a physically intuitive raydynamical interpretation. Special attention is paid to the role of diffraction and the finite side length.
 1. Department of Applied Physics, Yale University
 2. LPQM  Laboratoire de Photonique Quantique et Moléculaire
 3. SVI  Surface du Verre et Interfaces
 4. LPN  Laboratoire de photonique et de nanostructures
 5. CMLA  Centre de Mathématiques et de Leurs Applications
 6. Université de Liège
 7. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Partial transpose criteria for symmetric states
F. BohnetWaldraff ^{1, 2} D. Braun ^{2} O. Giraud ^{1}
Physical Review A, American Physical Society, 2016, 94 (4), pp.042343
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Eberhard Karls Universität Tübingen

Phase diagram of a graphene bilayer in the zeroenergy Landau level
Angelika Knothe ^{1, 2} Thierry Jolicoeur ^{2}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 94 (23), pp.235149
 1. University of Freiburg [Freiburg]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Phase transitions in ensembles of solitons induced by an optical pumping or a strong electric field
P. Karpov ^{1} S. Brazovskii ^{2}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 94 (12), pp.125108
 1. MISIS  National University of Science and Technology
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

PoissonBoltzmann thermodynamics of counterions confined by curved hard walls
Ladislav Samaj ^{1} E. Trizac ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2016, 93, pp.012601
We consider a set of identical mobile pointlike charges (counterions) confined to a domain with curved hard walls carrying a uniform fixed surface charge density, the system as a whole being electroneutral. Three domain geometries are considered: a pair of parallel plates, the cylinder and the sphere. The particle system in thermal equilibrium is assumed to be described by the nonlinear PoissonBoltzmann theory. While the effectively 1D plates and the 2D cylinder have already been solved, the 3D sphere problem is not integrable. It is shown that the contact density of particles at the charged surface is determined by a firstorder Abel differential equation of the second kind which is a counterpart of Enig's equation in the critical theory of gravitation and combustion/explosion. This equation enables us to construct the exact series solutions of the contact density in the regions of small and large surface charge densities. The formalism provides, within the meanfield PoissonBoltzmann framework, the complete thermodynamics of counterions inside a charged sphere (saltfree system).
 1. Institute of Physics, Slovak Academy of Sciences
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Postprocessing procedure for industrial quantum key distribution systems
Evgeny Kiktenko ^{1} Anton Trushechkin ^{2} Yury Kurochkin ^{3} Aleksey Fedorov ^{4, 3}
Journal of Physics: Conference Series, IOP Publishing, 2016, 741, pp.012081
 1. Bauman Moscow State Technical University
 2. SMI  Steklov Mathematical Institute
 3. Russian Quantum Center
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Quantum Levy flights and multifractality of dipolar excitations in a random system
X. Deng ^{1} B. L. Altshuler ^{2, 3} G. V. Shlyapnikov ^{4, 2, 5, 6, 7} L. Santos ^{1}
Physical Review Letters, American Physical Society, 2016, 117, pp.020401
We consider dipolar excitations propagating via dipoleinduced exchange among immobile molecules randomly spaced in a lattice. The character of the propagation is determined by longrange hops (Levy flights). We analyze the eigenenergy spectra and the multifractal structure of the wavefunctions. In 1D and 2D all states are localized, although in 2D the localization length can be extremely large leading to an effective localizationdelocalization crossover in realistic systems. In 3D all eigenstates are extended but not always ergodic, and we identify the energy intervals of ergodic and nonergodic states. The reduction of the lattice filling induces an ergodic to nonergodic transition, and the excitations are mostly nonergodic at low filling.
 1. LUH  Leibniz Universität Hannover [Hannover]
 2. Kavli Institute for Theoretical Physics
 3. Columbia University [New York]
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 5. VAN DER WAALSZEEMAN INSTITUTE  University of Amsterdam Van der WaalsZeeman Institute
 6. Russian Quantum Center
 7. Wuhan Institute of Physics and Mathematics

Quantumness of spin1 states
Fabian BohnetWaldraff ^{1, 2} Daniel Braun ^{2} Olivier Giraud ^{1}
Physical Review A, American Physical Society, 2016, 93, pp.012104
We investigate quantumness of spin1 states, defined as the HilbertSchmidt distance to the convex hull of spin coherent states. We derive its analytic expression in the case of pure states as a function of the smallest eigenvalue of the Bloch matrix and give explicitly the closest classical state for an arbitrary pure state. Numerical evidence is provided that the exact formula for pure states provides an upper bound on the quantumness of mixed states. Due to the connection between quantumness and entanglement we obtain new insights into the geometry of symmetric entangled states.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Institute für Theoretische Physik

RandomDiluted Triangular Plaquette Model: study of phase transitions in a Kinetically Constrained Model
Silvio Franz ^{1} Giacomo Gradenigo ^{2, 1, 3} Stefano Spigler ^{1}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2016, 93, pp.032601
We study how the thermodynamic properties of the Triangular Plaquette Model (TPM) are influenced by the addition of extra interactions. The thermodynamics of the original TPM is trivial, while its dynamics is glassy, as usual in Kinetically Constrained Models. As soon as we generalize the model to include additional interactions, a thermodynamic phase transition appears in the system. The additional interactions we consider are either short ranged, forming a regular lattice in the plane, or long ranged of the smallworld kind. In the case of longrange interactions we call the new model RandomDiluted TPM. We provide arguments that the model so modified should undergo a thermodynamic phase transition, and that in the longrange case this is a glass transition of the "Random FirstOrder" kind. Finally, we give support to our conjectures studying the finite temperature phase diagram of the RandomDiluted TPM in the Bethe approximation. This corresponds to the exact calculation on the random regular graph, where freeenergy and configurational entropy can be computed by means of the cavity equations.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LIPhy  Laboratoire Interdisciplinaire de Physique [Saint Martin d’Hères]
 3. CEA  CEA Saclay

Rare events statistics of random walks on networks: localization and other dynamical phase transitions
Caterina De Bacco ^{1} Alberto Guggiola ^{2} Reimer Kühn ^{3} Pierre Paga ^{3}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.184003
Rare event statistics for random walks on complex networks are investigated using the large deviations formalism. Within this formalism, rare events are realized as typical events in a suitably deformed pathensemble, and their statistics can be studied in terms of spectral properties of a deformed Markov transition matrix. We observe two different types of phase transition in such systems: (i) rare events which are singled out for sufficiently large values of the deformation parameter may correspond to {\em localized\/} modes of the deformed transition matrix, (ii) "modeswitching transitions" may occur as the deformation parameter is varied. Details depend on the nature of the observable for which the rare event statistics is studied, as well as on the underlying graph ensemble. In the present letter we report on the statistics of the average degree of the nodes visited along a random walk trajectory in Erd\H{o}sR\'enyi networks. Large deviations rate functions and localization properties are studied numerically. For observables of the type considered here, we also derive an analytical approximation for the Legendre transform of the largedeviations rate function, which is valid in the large connectivity limit. It is found to agree well with simulations.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. Department of Mathematics, King's College London

Renormalized jellium model for colloidal mixtures
María Isabel García De Soria ^{1} Carlos E. Álvarez ^{2} Emmanuel Trizac ^{3}
Physical Review E , American Physical Society (APS), 2016, 94, pp.042609
 1. Fisica Teorica, Universidad de Sevilla
 2. Universidad del Rosario, Bogota
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Resonant pairing of excitons in semiconductor heterostructures
S. V. Andreev ^{1, 2, 3}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 94 (14), pp.140501 (15). <10.1103/PhysRevB.94.140501>
We suggest indirect excitons in twodimensional semiconductor heterostructures as a platform for the realization of a bosonic analog of the BardeenCooperSchrieffer superconductor. The quantum phase transition to a biexcitonic gapped state can be controlled in situ by tuning the electric field applied to the structure in the growth direction. The proposed playground should allow one to go to strongly correlated and hightemperature regimes, unattainable with Feshbach resonant atomic gases.
 1. ITMO  National Research University of Information Technologies, Mechanics and Optics [St. Petersburg]
 2. LOMA  Laboratoire Ondes et Matière d'Aquitaine
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Rich Polymorphic Behavior of Wigner Bilayers
Moritz Antlanger ^{1, 2} Gerhard Kahl ^{1} Martial Mazars ^{2} Ladislav Šamaj ^{3, 4} Emmanuel Trizac ^{4}
Physical Review Letters, American Physical Society, 2016, 117 (11), pp.118002
 1. Vienna University of Technology [Vienna]
 2. LPT  Laboratoire de Physique Théorique d'Orsay [Orsay]
 3. Institute of Physics, Slovak Academy of Sciences
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Scattering on two AharonovBohm vortices
Eugene Bogomolny ^{1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.485202
The problem of two AharonovBohm (AB) vortices for the Helmholtz equation is examined in detail. It is demonstrated that the method proposed in [J. M. Myers, J. Math. Phys. \textbf{6}, 1839 (1963)] for diffraction on a slit can be generalized to get an explicit solution for AB vortices. Due to singular nature of AB interaction the Green function and the scattering amplitude for two AB vortices obey a series of partial differential equations. Coefficients entering these equations, in their turn, fulfill ordinary nonlinear differential equations whose solutions can be obtained from a solution of the Painleve V (or III) equation. The asymptotics of necessary functions for very large and very small distances between two vortices are calculated explicitly. Taken together, it means that the problem of two AB vortices is integrable.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Schrödinger approach to mean field games
Igor Swiecicki ^{1, 2} Thierry Gobron ^{1} Denis Ullmo ^{2}
Physical Review Letters, American Physical Society, 2016, 116, pp.128701
Mean Field Games (MFG) provide a theoretical frame to model socioeconomic systems. In this letter, we study a particular class of MFG which shows strong analogies with the {\em nonlinear Schr\"odinger and GrossPitaevski equations} introduced in physics to describe a variety of physical phenomena ranging from deepwater waves to interacting bosons. Using this bridge many results and techniques developed along the years in the latter context can be transferred to the former. As an illustration, we study in some details an example in which the "players" in the mean field game are under a strong incentive to coordinate themselves.
 1. LPTM  Laboratoire de Physique Théorique et Modélisation
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Schrödinger Approach to Mean Field Games – Archive ouverte HAL
Igor Swiecicki ^{1} Thierry Gobron ^{2} Denis Ullmo ^{3}
Igor Swiecicki, Thierry Gobron, Denis Ullmo. Schrödinger Approach to Mean Field Games. Physical Review Letters, American Physical Society, 2016, 116 (12), ⟨10.1103/PhysRevLett.116.128701⟩. ⟨hal02923129⟩
 1. LPTM  UMR 8089  Laboratoire de Physique Théorique et Modélisation
 2. LPP  Laboratoire Paul Painlevé  UMR 8524
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Spectroscopic probe of the van der Waals interaction between polar molecules and a curved surface
Giuseppe Bimonte ^{1, 2} Thorsten Emig ^{3, 4, 5} R. L. Jaffe ^{6, 4} Mehran Kardar ^{4}
Physical Review A, American Physical Society, 2016, 94 (2), pp.022509
 1. Università degli studi di Napoli Federico II [Napoli]
 2. INFN, Sezione di Napoli  Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
 3. (MSC)2 UMI3466 CNRSMIT  MultiScale Material Science for Energy and Environment
 4. Massachussetts Institute of Technology
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. Center for Theoretical Physics and Laboratory for Nuclear Science

Spontaneous Symmetry Breaking and Phase Coexistence in TwoColor Networks
V. Avetisov ^{1, 2} A. Gorsky ^{3, 4} S. Nechaev ^{5, 6} O. Valba ^{1, 2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2016, 93, pp.012302
We have considered an equilibrium ensemble of large Erd\H{o}sRenyi topological random networks with fixed vertex degree and two types of vertices, black and white, prepared randomly with the bond connection probability, $p$. The network energy is a sum of all unicolor triples (either black or white), weighted with chemical potential of triples, $\mu$. Minimizing the system energy, we see for some positive $\mu$ formation of two predominantly unicolor clusters, linked by a "string" of $N_{bw}$ blackwhite bonds. We have demonstrated that the system exhibits critical behavior manifested in emergence of a wide plateau on the $N_{bw}(\mu)$curve, which is relevant to a spinodal decomposition in 1st order phase transitions. In terms of a string theory, the plateau formation can be interpreted as an entanglement between babyuniverses in 2D gravity. We have conjectured that observed classical phenomenon can be considered as a toy model for the chiral condensate formation in quantum chromodynamics.
 1. The Semenov Institute of Chemical Physics
 2. Department of Applied Mathematics
 3. IITP  Institute for Information Transmission Problems
 4. MIPT  Moscow Institute of Physics and Technology [Moscow]
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. P. N. Lebedev Physical Institute [Moscow]

Teleportation in an indivisible quantum system
E. O. Kiktenko ^{1} A. K. Fedorov ^{2} V. I. Man'Ko ^{3, 4}
Quantum Measurements and Quantum Metrology, 2016, 3 (1), pp.13
Teleportation protocol is conventionally treated as a method for quantum state transfer between two spatially separated physical carriers. Recent experimental progress in manipulation with highdimensional quantum systems opens a new framework for implementation of teleportation protocols. We show that the onequbit teleportation can be considered as a state transfer between subspaces of the whole Hilbert space of an indivisible eightdimensional system. We explicitly show all corresponding operations and discuss an alternative way of implementation of similar tasks.
 1. Bauman Moscow State Technical University
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. MIPT  Moscow Institute of Physics and Technology [Moscow]
 4. P. N. Lebedev Physical Institute of the Russian Academy of Sciences

Tensor eigenvalues and entanglement of symmetric states
F. BohnetWaldraff ^{1, 2} D. Braun ^{2} O. Giraud ^{1}
Physical Review A, American Physical Society, 2016, 94 (4), pp.042324
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Physikalisches Institut Tübingen

The 8vertex model with quasiperiodic boundary conditions
G. Niccoli ^{1} V. Terras ^{2}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.044001
We study the inhomogeneous 8vertex model (or equivalently the XYZ Heisenberg spin1/2 chain) with all kinds of integrable quasiperiodic boundary conditions: periodic, $\sigma^x$twisted, $\sigma^y$twisted or $\sigma^z$twisted. We show that in all these cases but the periodic one with an even number of sites $\mathsf{N}$, the transfer matrix of the model is related, by the vertexIRF transformation, to the transfer matrix of the dynamical 6vertex model with antiperiodic boundary conditions, which we have recently solved by means of Sklyanin's Separation of Variables (SOV) approach. We show moreover that, in all the twisted cases, the vertexIRF transformation is bijective. This allows us to completely characterize, from our previous results on the antiperiodic dynamical 6vertex model, the twisted 8vertex transfer matrix spectrum (proving that it is simple) and eigenstates. We also consider the periodic case for $\mathsf{N}$ odd. In this case we can define two independent vertexIRF transformations, both not bijective, and by using them we show that the 8vertex transfer matrix spectrum is doubly degenerate, and that it can, as well as the corresponding eigenstates, also be completely characterized in terms of the spectrum and eigenstates of the dynamical 6vertex antiperiodic transfer matrix. In all these cases we can adapt to the 8vertex case the reformulations of the dynamical 6vertex transfer matrix spectrum and eigenstates that had been obtained by $T$$Q$ functional equations, where the $Q$functions are elliptic polynomials with twistdependent quasiperiods. Such reformulations enables one to characterize the 8vertex transfer matrix spectrum by the solutions of some Bethetype equations, and to rewrite the corresponding eigenstates as the multiple action of some operators on a pseudovacuum state, in a similar way as in the algebraic Bethe ansatz framework.
 1. PhysENS  Laboratoire de Physique de l'ENS Lyon
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

The dynamics of filament assembly define cytoskeletal network morphology
Giulia Foffano ^{1} Nicolas Levernier ^{2} Martin Lenz ^{1}
Nature Communications, Nature Publishing Group, 2016, 7, pp.13827
The actin cytoskeleton is a key component in the machinery of eukaryotic cells, and it selfassembles out of equilibrium into a wide variety of biologically crucial structures. While the molecular mechanisms involved are well characterized, the physical principles governing the spatial arrangement of actin filaments are not understood. Here we propose that the dynamics of actin network assembly from growing filaments results from a competition between diffusion, bundling, and steric hindrance, and is responsible for the range of observed morphologies. Our model and simulations thus predict an abrupt dynamical transition between homogeneous and strongly bundled networks as a function of the actin polymerization rate. This suggests that cells may effect dramatic changes to their internal architecture through minute modifications of their nonequilibrium dynamics. Our results are consistent with available experimental data.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée

The excitonic insulator route through a dynamical phase transition induced by an optical pulse
Serguei Brazovskii ^{1} Natasha Kirova ^{2}
Journal of Experimental and Theoretical Physics (JETP) / Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki, MAIK Nauka/Interperiodica, 2016, 149, pp.479
We consider a dynamical phase transition induced by a short optical pulse in a system prone to thermodynamical instability. We address the case of pumping to excitons whose density contributes directly to the order parameter. To describe both thermodynamic and dynamic effects on equal footing, we adopt a view of the excitonic insulator for the phase transition and suggest a formation of the Bose condensate for the pumped excitons. The work is motivated by experiments in donoracceptor organic compounds with a neutralionic phase transition coupled to the spontaneous lattice dimerization and to charge transfer excitons. The double nature of the ensemble of excitons leads to an intricate time evolution, in particular to macroscopic quantum oscillations from the interference between the Bose condensate of excitons and the ground state of the excitonic insulator. The coupling of excitons and the order parameter also leads to selftrapping of their wave function, akin to selffocusing in optics. The locally enhanced density of excitons can surpass a critical value to trigger the phase transformation, even if the mean density is below the required threshold. The system is stratified in domains that evolve through dynamical phase transitions and sequences of merging.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPS  Laboratoire de Physique des Solides

The free energy of a liquid when viewed as a population of overlapping clusters
Pierre Ronceray ^{1} Peter Harrowell ^{2}
Molecular Simulation, Taylor & Francis, 2016, 42, pp.1149
The expression of the free energy of a liquid in terms of an explicit decomposition of the particle configurations into local coordination clusters is examined. We argue that the major contribution to the entropy associated with structural fluctuations arises from the local athermal constraints imposed by the overlap of adjacent coordination shells. In the context of the recently developed Favoured Local Structure model [Soft Matt. 11, 3322 (2015)], we derive explicit expressions for the structural energy and entropy in the high temperature limit, compare this approximation with simulation data and consider the extension of this free energy to the case of spatial inhomogeneity in the distribution of local structures.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Faculty of Sciences

The jamming transition in high dimension: an analytical study of the TAP equations and the effective thermodynamic potential
Ada Altieri ^{1, 2} Silvio Franz ^{2} Giorgio Parisi ^{3, 1}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, 2016 (9), pp.093301
 1. SMC/INFM  Department of Physics, Sapienza University of Rome
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. INFN  Istituto Nazionale di Fisica Nucleare [Sezione di Roma 1]

The simplest model of jamming
Silvio Franz ^{1} Giorgio Parisi ^{2}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2016, 49, pp.145001
We study a well known machine learning model the perceptron as a simple model of jamming of hard objects. We exhibit two regimes: 1) a convex optimisation regime where jamming is hypostatic and noncritical. 2) a non convex optimisation regime where jamming is isostatic and critical. We characterise the critical jamming phase through exponents describing the distributions law of forces and gaps. Surprisingly we find that these exponents coincide with the corresponding ones recently computed in high dimensional hard spheres. In addition, modifying the perceptron to a random linear programming problem, we show that isostaticity is not a sufficient condition for singular force and gap distributions. For that, fragmentation of the space of solutions (replica symmetry breaking) appears to be a crucial ingredient. We hypothesise universality for a large class of nonconvex constrained satisfaction problems with continuous variables.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Dipartimento di Fisica and INFM

Thermalization and manybody localization in systems under dynamic nuclear polarization
Andrea De Luca ^{1} Inés RodríguezArias ^{1} Markus Müller ^{2, 3, 4} Alberto Rosso ^{1}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2016, 94 (1), pp.014203
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Paul Scherrer Institute
 3. The Abdus Salam International Centre for Theoretical Physics
 4. Unibas  University of Basel

Time and temperaturedependent correlation function of an impurity in a onedimensional Fermi gas as a Fredholm determinant
O. Gamayun ^{1} Andrei G. Pronko ^{2} Mikhail B. Zvonarev ^{3, 4}
New Journal of Physics, Institute of Physics: Open Access Journals, 2016, 18, pp.045005
We investigate a free onedimensional spinless Fermi gas, and the TonksGirardeau gas interacting with a single impurity particle of equal mass. We obtain a Fredholm determinant representation for the timedependent correlation function of the impurity particle. This representation is valid for an arbitrary temperature and an arbitrary repulsive or attractive impuritygas $\delta$function interaction potential. It includes, as particular cases, the representations obtained for zero temperature and arbitrary repulsion in [Nucl. Phys. B 892, 83 (2015)], and for arbitrary temperature and infinite repulsion in [Nucl. Phys. B 520, 594 (1998)].
 1. INSTITUUT LORENTZ  Instituut Lorentz
 2. Steklov Institute of Mathematics at St. Petersburg
 3. ITMO  National Research University of Information Technologies, Mechanics and Optics [St. Petersburg]
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Topological phase transitions in the 1D multichannel Dirac equation with random mass and a random matrix model
Aur Grabsch ^{1, 2} Christophe Texier ^{2}
Europhys.Lett., 2016, 〈10.1209/02955075/116/17004〉
We establish the connection between a multichannel disordered model —the 1D Dirac equation with $N\times N$ matrix random mass— and a random matrix model corresponding to a deformation of the Laguerre ensemble. This allows us to derive exact determinantal representations for the density of states and identify its lowenergy $(\varepsilon\to0)$ behaviour $\rho(\varepsilon)\sim\varepsilon^{\alpha1}$ . The vanishing of the exponent α for N specific values of the averaged mass over disorder ratio corresponds to N phase transitions of topological nature characterised by the change of a quantum number (Witten index) which is deduced straightforwardly in the matrix model.
 1. ENS Cachan  École normale supérieure  Cachan
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Tracer diffusion coefficients in a sheared inelastic Maxwell gas
Vicente Garzó ^{1} Emmanuel Trizac ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2016, pp.073206
We study the transport properties of an impurity in a sheared granular gas, in the framework of the Boltzmann equation for inelastic Maxwell models. We investigate here the impact of a nonequilibrium phase transition found in such systems, where the tracer species carries a finite fraction of the total kinetic energy (ordered phase). To this end, the diffusion coefficients are first obtained for a granular binary mixture in spatially inhomogeneous states close to the simple shear flow. In this situation, the set of coupled Boltzmann equations are solved by means of a ChapmanEnskoglike expansion around the (local) shear flow distributions for each species, thereby retaining all the hydrodynamic orders in the shear rate $a$. Due to the anisotropy induced by the shear flow, three tensorial quantities $D_{ij}$, $D_{p,ij}$, and $D_{T,ij}$ are required to describe the mass transport process instead of the conventional scalar coefficients. These tensors are given in terms of the solutions of a set of coupled algebraic equations, which can be \emph{exactly} solved as functions of the shear rate $a$, the coefficients of restitution $\alpha_{sr}$ and the parameters of the mixture (masses and composition). Once the forms of $D_{ij}$, $D_{p,ij}$, and $D_{T,ij}$ are obtained for arbitrary mole fraction $x_1=n_1/(n_1+n_2)$ (where $n_r$ is the number density of species $r$), the tracer limit ($x_1\to 0$) is carefully considered for the above three diffusion tensors. Explicit forms for these coefficients are derived showing that their shear rate dependence is significantly affected by the orderdisorder transition.
 1. Departamento de Fisica
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Ultradilute LowDimensional Liquids
D. s. Petrov ^{1} G. e. Astrakharchik ^{2}
Physical Review Letters, American Physical Society, 2016, 117 (10), pp.100401
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Departament de Fisica i Enginyeria Nuclear, Campus Nord B4B5

Universal threebody recombination and Efimov resonances in an ultracold LiCs mixture
J. Ulmanis ^{1} S. Häfner ^{1} R. Pires ^{1} F. Werner ^{2} D. S. Petrov ^{3} E. D. Kuhnle ^{1} M. Weidemüller ^{4, 1}
Physical Review A, American Physical Society, 2016, 93, pp.022707
We study Efimov resonances via threebody loss in an ultracold twocomponent gas of fermionic $^6$Li and bosonic $^{133}$Cs atoms close to a Feshbach resonance at 843~G, extending results reported previously [Pires \textit{et al.}, Phys. Rev. Lett. 112, 250404 (2014)] to temperatures around 120~nK. The experimental scheme for reaching lower temperatures is based upon compensating the gravityinduced spatial separation of the massimbalanced gases with bichromatic optical dipole traps. We observe the first and second excited LiCsCs Efimov resonance in the magnetic field dependence of the threebody event rate constant, in good agreement with the universal zerorange theory at finite temperature [Petrov and Werner, Phys. Rev. A 92, 022704 (2015)]. Deviations are found for the Efimov ground state, and the inelasticity parameter $\eta$ is found to be significantly larger than those for singlespecies systems.
 1. Physikalisches Institut, RuprechtKarlsUniversität Heidelberg
 2. LKB [Collège de France]  Laboratoire Kastler Brossel
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Hefei National Laboratory for Physical Sciences at the Microscale

Velocity Statistics of the NagelSchreckenberg Model
Nicolas Bain ^{1} Thorsten Emig ^{1, 2} FranzJoseph Ulm ^{3} Michael Schreckenberg ^{4}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2016, 93, pp.022305
The statistics of velocities in the cellular automaton model of Nagel and Schreckenberg for traffic are studied. From numerical simulations, we obtain the probability distribution function (PDF) for vehicle velocities and the velocityvelocity (vv) correlation function. We identify the probability to find a standing vehicle as a potential order parameter that signals nicely the transition between free congested flow for sufficiently large number of velocity states. Our results for the vv correlation function resemble features of a second order phase transition. We develop a 3body approximation that allows us to relate the PDFs for velocities and headways. Using this relation, an approximation to the velocity PDF is obtained from the headway PDF observed in simulations. We find a remarkable agreement between this approximation and the velocity PDF obtained from simulations.
 1. Massachussetts Institute of Technology
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Department of Civil and Environmental Engineering
 4. Universität DuisburgEssen [Essen]

Wigner time delay and related concepts: Application to transport in coherent conductors
Christophe Texier ^{1}
Physica E: Lowdimensional Systems and Nanostructures, Elsevier, 2016, 82, pp.16  33
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques