Exciting the Goldstone Modes of a Supersolid Spin-Orbit-Coupled Bose Gas

TL;DR

This paper proposes experimental signatures of Goldstone modes in a supersolid spin-orbit-coupled Bose gas, revealing distinct oscillation behaviors across a phase transition, thus advancing the understanding of supersolidity.

Contribution

It introduces accessible methods to detect Goldstone modes in trapped supersolid Bose gases, highlighting their behavior near the phase transition.

Findings

Hybridized density-spin mode excited above transition

Beating effect indicating spin-dipole Goldstone mode below transition

Evidence for translational Goldstone mode of stripes

Abstract

Supersolidity is deeply connected with the emergence of Goldstone modes, reflecting the spontaneous breaking of both phase and translational symmetry. Here, we propose accessible signatures of these modes in harmonically trapped spin-orbit-coupled Bose-Einstein condensates, where supersolidity appears in the form of stripes. By suddenly changing the trapping frequency, an axial breathing oscillation is generated, whose behavior changes drastically at the critical Raman coupling. Above the transition, a single mode of hybridized density and spin nature is excited, while below it, we predict a beating effect signaling the excitation of a Goldstone spin-dipole mode. We further provide evidence for the Goldstone mode associated with the translational motion of stripes. Our results open up new perspectives for probing supersolid properties in experimentally relevant configurations with both symmetric as well as highly asymmetric intraspecies interactions.