Linear response study of collisionless spin drag
Anno: 2021
Autori: Romito Donato; Lobo Carlos; Recati Alessio
Affiliazione autori: Univ Southampton, Sch Math Sci, Southampton SO17 1BJ, Hants, England; INO CNR BEC Trento, Via Sommar 14, I-38123 Povo, TN, Italy; Univ Trento, Dipartimento Fis, Via Rodolfo Belenzani 12, I-38122 Trento, TN, Italy.
Abstract: In this work we are concerned with the understanding of the collisionless drag or entrainment between two superfluids, also called Andreev-Bashkin effect, in terms of current response functions. The drag density is shown to be proportional to the cross transverse current-current response function, playing the role of a normal component for the single-species superfluid density. We can in this way link the existence of finite entrainment with the exhaustion of the energy-weighted sum rule in the spin channel. The formalism is then used to reproduce some known results for a weakly interacting Bose-Bose mixture. We include the drag effect to determine the beyond mean-field correction on the speed of sound and on the spin dipole excitations for a homogeneous and a trapped weakly interacting gas, respectively. Finally, we show that the response to a quick dipole perturbation on one of the species induces a dipole moment on the other species which is proportional to the drag at short times.
Giornale/Rivista: PHYSICAL REVIEW RESEARCH
Volume: 3 (2) Da Pagina: 023196-1 A: 023196-12
Parole chiavi: BoseDOI: 10.1103/PhysRevResearch.3.023196Citazioni: 10dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2025-05-04Riferimenti tratti da Isi Web of Knowledge: (solo abbonati) Link per visualizzare la scheda su IsiWeb: Clicca quiLink per visualizzare la citazioni su IsiWeb: Clicca qui
