Josephson dynamics of a spin-orbit coupled Bose-Einstein condensate in a double well potential

TL;DR

This paper explores the complex quantum dynamics of a spin-orbit coupled Bose-Einstein condensate in a double well, revealing coupled Josephson effects and spin currents that could be observed experimentally.

Contribution

It demonstrates the coexistence and coupling of internal and external Josephson effects, including spin-dependent tunneling and spin currents, in a spin-orbit coupled BEC system.

Findings

Spin-orbit coupling enhances inter-well tunneling.

Internal and external Josephson effects coexist and are coupled.

Spin-dependent tunneling induces observable spin currents.

Abstract

We investigate the quantum dynamics of an experimentally realized spin-orbit coupled Bose-Einstein condensate in a double well potential. The spin-orbit coupling can significantly enhance the atomic inter-well tunneling. We find the coexistence of internal and external Josephson effects in the system, which are moreover inherently coupled in a complicated form even in the absence of interatomic interactions. Moreover, we show that the spin-dependent tunneling between two wells can induce a net atomic spin current referred as spin Josephson effects. Such novel spin Josephson effects can be observable for realistically experimental conditions.