Ultracold Bosonic Atoms in Disordered Optical Superlattices

TL;DR

This paper explores how disorder affects ultracold bosonic atoms in quasiperiodic optical lattices, revealing a complex phase diagram with superfluid, Mott insulator, Bose-glass, and Anderson localized phases, and discusses experimental signatures.

Contribution

It demonstrates that simple periodic modulations in well depths lead to a rich phase diagram in the Bose-Hubbard model, including the Bose-glass phase, and analyzes experimental detection methods.

Findings

Identification of multiple phases including Bose-glass and Anderson localization.

Analysis of how modulation amplitude and interaction strength influence phases.

Proposals for experimental signatures in matter-wave interference patterns.

Abstract

The influence of disorder on ultracold atomic Bose gases in quasiperiodic optical lattices is discussed in the framework of the one-dimensional Bose-Hubbard model. It is shown that simple periodic modulations of the well depths generate a rich phase diagram consisting of superfluid, Mott insulator, Bose-glass and Anderson localized phases. The detailed evolution of mean occupation numbers and number fluctuations as function of modulation amplitude and interaction strength is discussed. Finally, the signatures of the different phases, especially of the Bose-glass phase, in matter-wave interference experiments are investigated.