Interaction Induced Hall Response in a Spin-Orbit Coupled Bose-Einstein Condensate

TL;DR

This paper investigates the dynamic responses of spin-orbit coupled Bose-Einstein condensates, revealing an interaction-induced ac Hall effect and contrasting behaviors in two distinct phases, with implications for understanding quantum fluid responses.

Contribution

It demonstrates the existence of an interaction-induced ac Hall response in spin-orbit coupled BECs and characterizes phase-dependent dynamic behaviors, including a novel Hall effect absent in non-interacting systems.

Findings

Interaction-induced ac Hall response exists in the condensate.

In the plane wave phase, ac longitudinal current induces transverse radial current.

In the stripe phase, density stripe sliding dominates the response.

Abstract

In this letter we consider the dynamic behaviors of spin-orbit coupled Bose condensates realized in recent experiments. We show that there exists an interaction induced ac Hall response which is absent in a non-interacting system. This condensate has two distinct equilibrium phases known as the plane wave phase and the stripe phase. In the plane wave phase, we show that an ac longitudinal current will induce an ac radial current in the transverse direction, and vice versa, as a cooperation effect of spin-velocity locking and spin-dependent interaction. In the stripe phase, we show that the dominant longitudinal response to a transverse radial current is sliding of the density stripe, because it is the low-lying excitation mode originated from spontaneous spatial translational symmetry breaking in this phase.