Dynamical preparation of an atomic condensate in a Hofstadter band

TL;DR

This paper demonstrates a method to dynamically create a Hofstadter Bose-Einstein condensate in cold atoms, overcoming heating challenges through specific protocols, and reveals complex evolution including a chaotic stage and reentrant BEC formation.

Contribution

It introduces a novel experimental protocol for realizing a Hofstadter BEC via dynamical modulation, addressing heating issues and showing complex evolution dynamics.

Findings

Successful dynamical realization of Hofstadter BEC

Identification of a chaotic intermediate heating stage

Observation of spontaneous reentrance to BEC

Abstract

The creation of a Hamiltonian in the quantum regime which has non-trivial topological features is a central goal of the cold-atom community, enabling widespread exploration of novel phases of quantum matter. A general scheme to synthesize such Hamiltonians is based on dynamical modulation of optical lattices which thereby generate vector potentials. At the same time the modulation can lead to heating and serious difficulties with equilibration. Here we show that these challenges can be overcome by demonstrating how a Hofstadter Bose-Einstein condensate (BEC) can be dynamically realized, using experimental protocols. From Gross-Pitaevskii simulations our study reveals a complex, multistage evolution; this includes a chaotic intermediate "heating" stage followed by a spontaneous reentrance to the BEC. The observed behavior is reminiscent of evolution in cosmological models.