Abstract
We employ the Bogoliubov approximation to study how the quantum geometry of the helicity states affects the superfluid properties of a spin-orbit-coupled Bose gas in continuum. In particular we derive the low-energy Bogoliubov spectrum for a plane-wave condensate in the lower helicity band and show that the geometric contributions to the sound velocity are distinguished by their linear dependences on the interaction strength; that is, they are in sharp contrast to the conventional contribution which has a square-root dependence. We also discuss the roton instability of the plane-wave condensate against the stripe phase and determine their phase-transition boundary. In addition we derive the superfluid density tensor by imposing a phase twist on the condensate order parameter and study the relative importance of its contribution from the interband processes that is related to the quantum geometry.
Original language | English |
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Article number | 023301 |
Journal | Physical Review A |
Volume | 105 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2022 |
Bibliographical note
Publisher Copyright:© 2022 American Physical Society.
Funding
We thank A. Julku for email correspondence, and M.I. acknowledges funding from TÜBİTAK Grant No. 1001-118F359.
Funders | Funder number |
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TÜBİTAK | 1001-118F359 |