Emergence of Topological and Strongly Correlated Ground States in trapped Rashba Spin-Orbit Coupled Bose Gases

TL;DR

This paper investigates the ground states of Rashba spin-orbit coupled Bose gases in a trap, revealing topological vortex states at small particle numbers and strongly correlated states at larger numbers and interactions.

Contribution

It provides a comprehensive phase diagram for few- to many-body regimes, highlighting the emergence of topological and strongly correlated ground states in trapped Rashba Bose gases.

Findings

Bosons condense into topological vortex states at small particle numbers.

At larger particle numbers, ground states align with mean-field predictions at weak interactions.

Strong interactions lead to the emergence of strongly correlated ground states.

Abstract

We theoretically study an interacting few-body system of Rashba spin-orbit coupled two-component Bose gases confined in a harmonic trapping potential. We solve the interacting Hamiltonian at large Rashba coupling strengths using Exact Diagonalization scheme, and obtain the ground state phase diagram for a range of interatomic interactions and particle numbers. At small particle numbers, we observe that the bosons condense to an array of topological states with n+1/2 quantum angular momentum vortex configurations, where n = 0, 1, 2, 3... At large particle numbers, we observe two distinct regimes: at weaker interaction strengths, we obtain ground states with topological and symmetry properties that are consistent with mean-field theory computations; at stronger interaction strengths, we report the emergence of strongly correlated ground states.