Stationary States of Trapped Spin-Orbit-Coupled Bose-Einstein Condensates

TL;DR

This paper numerically studies low-energy stationary states of spin-orbit-coupled Bose-Einstein condensates, revealing vortex lattice formations and conditions for different ground states, with implications for experimental observation.

Contribution

It provides a numerical and analytical analysis of stationary states in spin-orbit-coupled BECs, highlighting vortex lattice ground states under strong coupling.

Findings

Strong spin-orbit coupling leads to square vortex lattice ground states.

Weak coupling can host single vortex states.

Certain stationary states are analytically shown not to be ground states.

Abstract

We numerically investigate low-energy stationary states of pseudospin-1 Bose-Einstein condensates in the presence of Rashba-Dresselhaus-type spin-orbit coupling. We show that for experimentally feasible parameters and strong spin-orbit coupling, the ground state is a square vortex lattice irrespective of the nature of the spin-dependent interactions. For weak spin-orbit coupling, the lowest-energy state may host a single vortex. Furthermore, we analytically derive constraints that explain why certain stationary states do not emerge as ground states. Importantly, we show that the distinct stationary states can be observed experimentally by standard time-of-flight spinindependent absorption imaging.