Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:0912.1117 · Physical Review A

Diffusion of cold-atomic gases in the presence of an optical speckle potential

Leonid Beilin, E. Gurevich, Boris Shapiro

Published Mar 18, 2010• 13 citations
arXivHTMLPDF

Abstract

We consider diffusion of a cold Fermi gas in the presence of a random optical speckle potential. The evolution of the initial atomic cloud in space and time is discussed. Analytical and numerical results are presented in various regimes. Diffusion of a Bose-Einstein condensate is also briefly discussed and similarity with the Fermi gas case is pointed out.

DOI
10.1103/physreva.81.033612

Related papers

Density correlations in cold atomic gases: Atomic speckles in the presence of disorder

Peter Henseler, Boris Shapiro

The phenomenon of random intensity patterns, for waves propagating in the presence of disorder, is well known in optics and in mesoscopic physics. We study this phenomenon for cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered.

arXiv:0801.4858•Physical Review A•Mar 21, 2008•16 citations

Dynamic evolution of expanding Bose–Einstein condensates in the presence of a three-dimensional random optical speckle potential

Afifa Yedjour, Hanane Benmahdjoub, Abdelâali Boudjemâa

Abstract We study the diffusion of an expanding Bose–Einstein condensate released from a harmonic trap in a three-dimensional speckle disorder potential. To this end, we use the first Born approximation and examine the density profiles at short and long times. Analytical results are presented in different regimes. The evolution of the density profiles in space and time is deeply examined. We find that at long times and for a fixed disorder strength, the profile of the average atomic density decreases in power law. The time evolution of the typical size of the condensate is explored numerically.

Physica Scripta•Jan 10, 2022•5 citations

Regimes of classical transport of cold gases in a two-dimensional anisotropic disorder

Luca Pezzè, Martin Robert-De-Saint-Vincent, Thomas Bourdel +6 more

We numerically study the dynamics of cold atoms in a twodimensional disordered potential.We consider an anisotropic speckle potential and focus on the classical dynamics, which is relevant to some recent experiments.Firstly, we study the behavior of particles with a fixed energy and identify different transport regimes.At low energy, the particles are classically localized due to the absence of a percolating cluster.At high energy, the particles undergo normal diffusion, and we show that the diffusion coefficients scale algebraically with the particle energy, with an anisotropy factor that is significantly different from that of the disordered potential.At intermediate energy, we find a transient sub-diffusive regime, which is relevant to the time scale of typical experiments.Secondly, we study the behavior of a cold atomic gas with an arbitrary energy distribution, using the above results as the groundwork.We show that the density profile of the atomic cloud in the diffusion regime is strongly peaked and, in particular, that it is not Gaussian.Its behavior at large distances allows us to extract the energy-dependent diffusion coefficients from experimental density distributions.For a thermal cloud released into the disordered potential, we show that our numerical predictions are in

arXiv:1103.2294•New Journal of Physics•Sep 26, 2011•39 citations

Coherent Transport of Matter Waves in Disordered Optical Potentials

KUHN, Robert, Cord Axel Müller, Christian Miniatura

The development of atom cooling and trapping techniques and the ability to load optical lattices or disordered potentials with Bose-Einstein condensates or degenerate Fermi gases has opened a whole field of research around the strong localization of matter waves. In this theoretical work we study the coherent transport of matter waves evolving in disordered optical potentials (speckle). The influence of correlated disorder is first studied numerically in the framework of the Anderson model. Subsequently, a self-consistent diagrammatic calculation allows us to determine analytically the basic transport parameters in the regime of weak disorder: mean free path, transport mean free path, diffusion constant, localization length. A crucial quantity for these analytical calculations is the spatial correlation function of speckle fluctuations. It determines the degree of anisotropy of a scattering event. We consider in particular the transition from weak localization to strong localization. In this case the diffusion constant of matter waves decreases and approaches zero at the threshold of strong localization. We calculate the renormalization of the diffusion constant due to the interference of matter waves by explicitly considering the correlation of fluctuations of the disordered potential.

•Jan 1, 2007•6 citations

Cold Atomic Gases in Optical Lattices with Disorder

T. Schulte, S. Drenkelforth, J. Kruse +10 more

Cold atomic gases placed in optical lattices enable studies of simple condensed matter theory models with parameters that may be tuned relatively easily.When the optical potential is randomized (e.g. using laser speckle to create a random intensity distribution) one may be able to observe Anderson localization of matter waves for non-interacting bosons, the so-called Bose glass in the presence of interactions, as well as the Fermi glass or quantum spin glass for mixtures of fermions and bosons.

Acta Physica Polonica A•Jan 1, 2006•4 citations

Diffusion and Localization of Cold Atoms in 3D Optical Speckle

Afifa Yedjour, Bart A. van Tiggelen

In this work we re-formulate and solve the self-consistent theory for localization to a Bose-Einstein condensate expanding in a 3D optical speckle. The long-range nature of the fluctuations in the potential energy, treated in the self-consistent Born approximation, make the scattering strongly velocity dependent, and its consequences for mobility edge and fraction of localized atoms have been investigated numerically.

arXiv:0912.4224•Dec 21, 2009•19 citations
We consider diffusion of a cold Fermi gas in the presence of a random optical speckle potential. The evolution of the initial atomic cloud in space and time is discussed. Analytical and numerical results are presented in various regimes. Diffusion of a Bose-Einstein condensate is also briefly discussed and similarity with the Fermi gas case is pointed out.
The phenomenon of random intensity patterns, for waves propagating in the presence of disorder, is well known in optics and in mesoscopic physics. We study this phenomenon for cold atomic gases expanding, by a diffusion process, in a weak random potential. We show that the density-density correlation function of the expanding gas is strongly affected by disorder and we estimate the typical size of a speckle spot, i.e., a region of enhanced or depleted density. Both a Fermi gas and a Bose-Einstein condensate (in a mean-field approach) are considered.
Abstract We study the diffusion of an expanding Bose–Einstein condensate released from a harmonic trap in a three-dimensional speckle disorder potential. To this end, we use the first Born approximation and examine the density profiles at short and long times. Analytical results are presented in different regimes. The evolution of the density profiles in space and time is deeply examined. We find that at long times and for a fixed disorder strength, the profile of the average atomic density decreases in power law. The time evolution of the typical size of the condensate is explored numerically.
We numerically study the dynamics of cold atoms in a twodimensional disordered potential.We consider an anisotropic speckle potential and focus on the classical dynamics, which is relevant to some recent experiments.Firstly, we study the behavior of particles with a fixed energy and identify different transport regimes.At low energy, the particles are classically localized due to the absence of a percolating cluster.At high energy, the particles undergo normal diffusion, and we show that the diffusion coefficients scale algebraically with the particle energy, with an anisotropy factor that is significantly different from that of the disordered potential.At intermediate energy, we find a transient sub-diffusive regime, which is relevant to the time scale of typical experiments.Secondly, we study the behavior of a cold atomic gas with an arbitrary energy distribution, using the above results as the groundwork.We show that the density profile of the atomic cloud in the diffusion regime is strongly peaked and, in particular, that it is not Gaussian.Its behavior at large distances allows us to extract the energy-dependent diffusion coefficients from experimental density distributions.For a thermal cloud released into the disordered potential, we show that our numerical predictions are in
The development of atom cooling and trapping techniques and the ability to load optical lattices or disordered potentials with Bose-Einstein condensates or degenerate Fermi gases has opened a whole field of research around the strong localization of matter waves. In this theoretical work we study the coherent transport of matter waves evolving in disordered optical potentials (speckle). The influence of correlated disorder is first studied numerically in the framework of the Anderson model. Subsequently, a self-consistent diagrammatic calculation allows us to determine analytically the basic transport parameters in the regime of weak disorder: mean free path, transport mean free path, diffusion constant, localization length. A crucial quantity for these analytical calculations is the spatial correlation function of speckle fluctuations. It determines the degree of anisotropy of a scattering event. We consider in particular the transition from weak localization to strong localization. In this case the diffusion constant of matter waves decreases and approaches zero at the threshold of strong localization. We calculate the renormalization of the diffusion constant due to the interference of matter waves by explicitly considering the correlation of fluctuations of the disordered potential.