1999

X-Ray Diffraction from Pinned Charge Density Waves

S. Rouziere 1, S. Ravy 2, S. Brazovskii 3, J. -P. Pouget 2 Journal de Physique IV Colloque 9 (1999) Pr10-23 We present an x-ray study of doped charge density waves systems. When a 2k_f-charge density wave is strongly pinned to impurities, an interference effect gives rise to an asymmetry between the intensities of the +2k_f and -2k_f satellite reflections. Moreover, profile asymmetry …

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Vortices in Ginzburg-Landau billiards

E. Akkermans 1, K. Mallick 1 Journal of Physics A 32 (1999) 7133-7143 We present an analysis of the Ginzburg-Landau equations for the description of a two-dimensional superconductor in a bounded domain. Using the properties of a special integrability point of these equations which allows vortex solutions, we obtain a closed expression for the energy of the superconductor. The …

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Universality of the Wigner time delay distribution for one-dimensional random potentials

Christophe Texier 1, Alain Comtet 1 Physical Review Letters 82 (1999) 4220-4223 We show that the distribution of the time delay for one-dimensional random potentials is universal in the high energy or weak disorder limit. Our analytical results are in excellent agreement with extensive numerical simulations carried out on samples whose sizes are large compared to the localisation length …

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Universality in quantum parametric correlations

P. Leboeuf 1, M. Sieber 1, 2 Physical Review E: Statistical, Nonlinear, and Soft Matter Physics 60 (1999) 3969-3972 We investigate the universality of correlation functions of chaotic and disordered quantum systems as an external parameter is varied. A new, general scaling procedure is introduced which makes the theory invariant under reparametrizations. Under certain general conditions we show that this …

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Topological coupling of dislocations and magnetization vorticity in Spin Density Waves

S. Brazovski 1, N. Kirova 1 Journal de Physique IV Colloque 9 (1999) Pr10-121 The rich order parameter of Spin Density Waves allows for an unusual object of a complex topological nature: a half-integer dislocation combined with a semi-vortex of the staggered magnetization. It becomes energetically preferable to ordinary dislocation due to enhanced Coulomb interactions in the semiconducting regime. …

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Theory of plastic flows of CDWs in application to the current conversion

S. Brazovski 1, N. Kirova 1 Journal de Physique IV Colloque 9 (1999) Pr10-143 We suggest a theoretical picture for distributions of plastic deformations experienced by a sliding Charge Density Wave in the course of the conversion from the normal current at the contact to the collective one in the bulk. Several mechanisms of phase slips via creation and …

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The stochastic traveling salesman problem: Finite size scaling and the cavity prediction

A. G. Percus 1, O. C. Martin 2 Journal of Statistical Physics 94 (1999) 739-758 We study the random link traveling salesman problem, where lengths l_ij between city i and city j are taken to be independent, identically distributed random variables. We discuss a theoretical approach, the cavity method, that has been proposed for finding the optimal tour length …

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Statistical properties of the time evolution of complex systems. I

P. Leboeuf 1, G. Iacomelli The time evolution of a bounded quantum system is considered in the framework of the orthogonal, unitary and symplectic circular ensembles of random matrix theory. For an $N$ dimensional Hilbert space we prove that in the large $N$ limit the return amplitude to the initial state and the transition amplitude to any other …

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