Spin-orbit-coupled Bose-Einstein condensates held under toroidal trap

TL;DR

This paper investigates the complex ground and metastable states of a spin-orbit-coupled Bose-Einstein condensate confined in a toroidal trap, revealing diverse patterns and vortex configurations as the trap geometry varies.

Contribution

It introduces a detailed analysis of spin-orbit-coupled BECs in toroidal traps, highlighting the emergence of novel structures and vortex states, including the fragmented condensate in a ring geometry.

Findings

Identification of various ground and metastable states including triangular stripes and flower-petal patterns.

Observation of exotic vortex configurations in rotating systems.

Discovery of a fragmented condensate in the quasi-one-dimensional ring limit.

Abstract

We study a quasispin-$1/2$ Bose-Einstein condensate with synthetically generated spin-orbit coupling in a toroidal trap, and show that the system has a rich variety of ground and metastable states. As the central hole region increases, i.e., the potential changes from harmonic-like to ring-like, the condensate exhibits a variety of structures, such as triangular stripes, flower-petal patterns, and counter-circling states. We also show that the rotating systems have exotic vortex configurations. In the limit of a quasi-one dimensional ring, the quantum many-body ground state is obtained, which is found to be the fragmented condensate.