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

Year: 2021

Authors: Geier K.T., Martone G.I., Hauke P., Stringari S.

Autors Affiliation: Univ Trento, INO CNR BEC Ctr, I-38123 Povo, Italy; Univ Trento, Dipartimento Fis, I-38123 Povo, Italy; Heidelberg Univ, Inst Theoret Phys, Philosophenweg 16, D-69120 Heidelberg, Germany; Sorbonne Univ, ENS PSL Res Univ, Coll France, Lab Kastler Brossel,CNRS, 4 Pl Jussieu, F-75005 Paris, France

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.


Volume: 127 (11)      Pages from: 115301-1  to: 115301-6

More Information: We thank Li Chen, Han Pu, Jean Dalibard, Gabriele Ferrari, and the ICFO team led by Leticia Tarruell for fruitful discussions. This project has received funding from the European Research Council (ERC) under the European Union´s Horizon 2020 research and innovation programme (ERC StG StrEnQTh, Grant Agreement No. 804305), the Provincia Autonoma di Trento, and Q@TN – Quantum Science and Technology inTrento. The authors acknowledge support by the state of Baden-Wurttemberg throughbwHPC.
KeyWords: Bose-Einstein condensates; superfluidity
DOI: 10.1103/PhysRevLett.127.115301