Properties of Bose Gases with Raman-Induced Spin-Orbit Coupling

TL;DR

This paper explores how Raman-induced spin-orbit coupling affects Bose gases, revealing modifications in density-of-states, condensate depletion, transition temperatures, and critical velocities, with implications for cold atom experiments.

Contribution

It provides a comprehensive analysis of the effects of spin-orbit coupling on Bose gases, including non-monotonic behaviors and broken Galilean invariance, which are novel insights.

Findings

Spin-orbit coupling modifies the density-of-states.

It causes non-monotonic condensate depletion and energy corrections.

It introduces two different critical velocities and affects transition temperatures.

Abstract

In this paper we investigate the properties of Bose gases with Raman-induced spin-orbit(SO) coupling. It is found that the SO coupling can greatly modify the single particle density-of-state, and thus lead to non-monotonic behavior of the condensate depletion, the Lee-Huang-Yang correction of ground-state energy and the transition temperature of a non-interacting Bose-Einstein condensate. The presence of the SO coupling also breaks the Galilean invariance, and this gives two different critical velocities, corresponding to the movement of the condensate and the impurity respectively. Finally, we show that with SO coupling, the interactions modify the BEC transition temperature even at Hartree-Fock level, in contrast to the ordinary Bose gas without SO coupling. All results presented here can be directly verified in the current cold atom experiments using Raman laser-induced gauge field.