Anomalous Doppler effect in two-component Bose-Einstein condensates
Year: 2025
Authors: Zawislak T., Stringari S., Recati A.
Autors Affiliation: Univ Trento, Pitaevskii BEC Ctr, CNR INO, Via Sommar 14, I-38123 Trento, Italy; Univ Trento, Dipartimento Fis, Via Sommar 14, I-38123 Trento, Italy; Trento Inst Fundamental Phys & Applicat, INFN, I-38123 Trento, Italy.
Abstract: We show that two-component Bose-Einstein condensed mixtures, in presence of a persistent current, exhibit a nontrivial Doppler shift of the sound velocities. The peculiarity is due to the interspecies interaction and the possibility of generating a counterflow persistent current. Analytical predictions are derived using superfluid hydrodynamics. While the existence of anomalous Doppler shifts at finite temperature has been discussed a long time ago in the case of superfluid 4He, an experimental verification of the effect is still missing. For this reason, we also propose a protocol for the measurement of the Doppler shifts, based on the density-density response function. The dynamical protocol is simulated by means of coupled Gross-Pitaevskii equations.
Journal/Review: PHYSICAL REVIEW A
Volume: 112 (6) Pages from: 63311-1 to: 63311-7
More Information: We acknowledge useful discussions with Gabriele Ferrari, Giacomo Lamporesi, and Marija & Scaron;indik. This work has been supported by the Provincia Autonoma di Trento, CINECA consortium through the award under the ISCRA initiative for the availability of HPC resources. Part of the work was computed on Deeplearning cluster supported by the initiative Dipartimenti di Eccellenza 2018-2022 (Legge 232/2016) funded by the MUR.KeyWords: 4th Sound; ShiftDOI: 10.1103/yc6t-13d4
