Ground State Properties of Spin-Orbit Coupled Bose Gases for Arbitrary Interactions

TL;DR

This paper develops a formalism to analyze the ground state properties of spin-orbit coupled Bose gases with arbitrary interactions, revealing how SOC influences stability, excitation spectra, and phase fluctuations.

Contribution

It introduces a field integral approach to study SOC Bose gases with arbitrary interactions, uncovering new features like roton minima and SOC effects on stability.

Findings

SOC induces a roton minimum in excitation spectrum

SOC can stabilize the system by reducing quantum depletion

Static structure factor remains unaffected by SOC in certain phases

Abstract

We develop a field integral formalism to study spin-orbit-coupled (SOC) Bose gases with arbitrary interspecies interaction. We identify various features arising from the interplay of SOC and interspecies interaction, including a roton minimum in the excitation spectrum and dual effects of SOC on ground-state energies depending on interspecies interactions. Counterintuitively, we find that at low interspecies interaction the SOC stabilizes the system by suppressing the quantum depletion. We show that the static structure factor is immune to the SOC in the phase space where time-reversal symmetry is preserved. Furthermore, we present an alternate way of studying phase fluctuations of the system.