Interacting bosons in topological optical flux lattices

TL;DR

This paper explores how interacting bosons in optical flux lattices can realize various topological quantum states, including fractional quantum Hall states, with controllable topological properties and stability considerations for experimental realization.

Contribution

It introduces a detailed analysis of bosonic interactions in optical flux lattices, revealing the emergence of fractional quantum Hall states and topological phases with higher Chern numbers.

Findings

Identification of conditions for fractional quantum Hall states in optical flux lattices

Analysis of stability of topological phases against band dispersion and mixing

Discovery of novel topological phases with Chern number greater than 1

Abstract

An interesting route to the realization of topological Chern bands in ultracold atomic gases is through the use of optical flux lattices. These models differ from the tight-binding real-space lattice models of Chern insulators that are conventionally studied in solid-state contexts. Instead, they involve the coherent coupling of internal atomic (spin) states, and can be viewed as tight-binding models in reciprocal space. By changing the form of the coupling and the number $N$ of internal spin states, they give rise to Chern bands with controllable Chern number and with nearly flat energy dispersion. We investigate in detail how interactions between bosons occupying these bands can lead to the emergence of fractional quantum Hall states, such as the Laughlin and Moore-Read states. In order to test the experimental realization of these phases, we study their stability with respect to band dispersion and band mixing. We also probe novel topological phases that emerge in these systems when the Chern number is greater than 1.