1997

Uniform approximation for diffractive contributions to the trace formula in billiard systems

Martin Sieber 1, 2, Nicolas Pavloff 1, Charles Schmit 1 Physical Review E: Statistical, Nonlinear, and Soft Matter Physics 55 (1997) 2279-2299 We derive contributions to the trace formula for the spectral density accounting for the role of diffractive orbits in two-dimensional billiard systems with corners. This is achieved by using the exact Sommerfeld solution for the Green function of a wedge. …

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The random link approximation for the Euclidean traveling salesman problem

N. J. Cerf 1, J. Boutet de Monvel 1, O. Bohigas 1, O. C. Martin 1, A. G. Percus 1 Journal de Physique I 7 (1997) 117-136 The traveling salesman problem (TSP) consists of finding the length of the shortest closed tour visiting N « cities\’\’. We consider the Euclidean TSP where the cities are distributed randomly and independently in a d-dimensional unit hypercube. Working with …

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Semiclassical Approach to Orbital Magnetism of Interacting Diffusive Quantum Systems

D. Ullmo 1, 2, K. Richter 3, H. U. Baranger 1, F. Von Oppen 4, R. A. Jalabert 5 Physica E: Low-dimensional Systems and Nanostructures 1 (1997) 238-273 We study interaction effects on the orbital magnetism of diffusive mesoscopic quantum systems. By combining many-body perturbation theory with semiclassical techniques, we show that the interaction contribution to the ensemble averaged quantum thermodynamic potential can be reduced to …

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Percolation Transition in the random antiferromagnetic spin-1 chain

C. Monthus 1, O. Golinelli 1, Th. Jolicoeur 1 Physical Review Letters 79 (1997) 3254-3257 We give a physical description in terms of percolation theory of the phase transition that occurs when the disorder increases in the random antiferromagnetic spin-1 chain between a gapless phase with topological order and a random singlet phase. We study the statistical properties of the percolation …

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On the distribution of the Wigner time delay in one-dimensional disordered systems

Alain Comtet 1, 2, Christophe Texier 2 Journal of Physics A 30 (1997) 8017-8025 We consider the scattering by a one-dimensional random potential and derive the probability distribution of the corresponding Wigner time delay. It is shown that the limiting distribution is the same for two different models and coincides with the one predicted by random matrix theory. It is …

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Mean field and corrections for the Euclidean Minimum Matching problem

Jacques Boutet de Monvel 1, Olivier C. Martin 1 Physical Review Letters 79 (1997) 167-170 Consider the length $L_{MM}^E$ of the minimum matching of N points in d-dimensional Euclidean space. Using numerical simulations and the finite size scaling law $< L_{MM}^E > = \\beta_{MM}^E(d) N^{1-1/d}(1+A/N+… )$, we obtain precise estimates of $\\beta_{MM}^E(d)$ for $2 \\le d \\le 10$. We …

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Hall Conductivity for Two Dimensional Magnetic Systems

Jean Desbois 1, Stephane Ouvry 1, Christophe Texier 1 Nuclear Physics B 500 (1997) 486-510 A Kubo inspired formalism is proposed to compute the longitudinal and transverse dynamical conductivities of an electron in a plane (or a gas of electrons at zero temperature) coupled to the potential vector of an external local magnetic field, with the additional coupling of the spin …

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Density Correlations of Magnetic Impurities and Disorder

Jean Desbois 1, Cyril Furtlehner 1, Stéphane Ouvry 1 Journal of Physics A 30 (1997) 7291-7300 We consider an electron coupled to a random distribution of point vortices in the plane (magnetic impurities). We analyze the effect of the magnetic impurities on the density of states of the test particle, when the magnetic impurities have a spatial probability distribution governed by …

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