Non-Abelian spin singlet states of two-component Bose gases in artificial gauge fields

TL;DR

This paper investigates strongly correlated two-component Bose gases in artificial gauge fields, identifying incompressible phases and topological states, including non-Abelian spin singlet states, and explores how spin-orbit coupling influences these phases.

Contribution

It introduces a classification of non-Abelian spin singlet states in two-component Bose gases and analyzes the effects of spin-orbit coupling on their topological phases.

Findings

Identification of incompressible phases at fillings =2k/3

Classification of states as non-Abelian spin singlet (NASS) states

Spin-orbit coupling induces transitions between NASS-like and spin-polarized phases

Abstract

We study strongly correlated phases of a pseudo-spin-1/2 Bose gas in an artificial gauge field using the exact diagonalization method. The atoms are confined in two dimensions and interact via a two-body contact potential. In Abelian gauge fields, pseudo-spin singlets are favored by pseudo-spin independent interactions. We find a series of incompressible phases at fillings \nu=2k/3. By comparison with the non-Abelian spin singlet (NASS) states, constructed as zero-energy eigenstates of a (k+1)-body contact interaction, we classify the non-trivial topology of the states. An additional spin-orbit coupling is shown to switch between NASS-like states and spin-polarized phases from the Read-Rezayi series.