skip to main content

SciTech ConnectSciTech Connect

Title: Transport of an interacting Bose gas in 1D disordered lattices

We use ultracold atoms in a quasiperiodic lattice to study two outstanding problems in the physics of disordered systems: a) the anomalous diffusion of a wavepacket in the presence of disorder, interactions and noise; b) the transport of a disordered superfluid. a) Our results show that the subdiffusion, observed when interaction alone is present, can be modelled with a nonlinear diffusion equation and the peculiar shape of the expanding density profiles can be connected to the microscopic nonlinear diffusion coefficients. Also when noise alone is present we can describe the observed normal diffusion dynamics by existing microscopic models. In the unexplored regime in which noise and interaction are combined, instead, we observe an anomalous diffusion, that we model with a generalized diffusion equation, where noise- and interaction-induced contributions add each other. b) We find that an instability appearing at relatively large momenta can be employed to locate the fluid-insulator crossover driven by disorder. By investigating the momentum-dependent transport, we observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. The set of critical disorder and interaction strengths for which such critical momentum vanishes, can be identified with the separation between amore » fluid regime and an insulating one and can be related to the predicted zero-temperature superfluid-Bose glass transition.« less
Authors:
; ; ; ; ; ; ;  [1]
  1. LENS and Dipartimento di Fisica e Astronomia, Università di Firenze, and CNR-INO, 50019 Sesto Fiorentino (Italy)
Publication Date:
OSTI Identifier:
22308260
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1610; Journal Issue: 1; Conference: TIDS15: 15. international conference on transport in interacting disordered systems, Sant Feliu de Guixols (Spain), 1-5 Sep 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOSE-EINSTEIN GAS; DIFFUSION EQUATIONS; FLUIDS; INTERACTIONS; NOISE; NONLINEAR PROBLEMS; SUPERFLUIDITY; WAVE PACKETS