Andreev-Bashkin effect in superfluid cold gases mixtures

© 2017 The Author(s). Published by IOP Publishing Ltd on behalf of Deutsche Physikalische Gesellschaft. We study a mixture of two superfluids with density-density and current-current (Andreev-Bashkin) interspecies interactions. The Andreev-Bashkin coupling gives rise to a dissipationless drag (or en...

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Detalles Bibliográficos
Autores: Nespolo, Jacopo, Astrakharchik, Grigori|||0000-0003-0394-8094, Recati, Alessio
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/113354
Acceso en línea:https://hdl.handle.net/2117/113354
https://dx.doi.org/10.1088/1367-2630/aa93a0
Access Level:acceso abierto
Palabra clave:Sum rules (Physics)
Monte Carlo method
Superfluidity
Andreev-Bashkin effect
diffusion quantum Monte Carlo
dipolar gases
multicomponent superfluids
sum rules
Montecarlo, Mètode de
Superfluïdesa
Àrees temàtiques de la UPC::Física
Descripción
Sumario:© 2017 The Author(s). Published by IOP Publishing Ltd on behalf of Deutsche Physikalische Gesellschaft. We study a mixture of two superfluids with density-density and current-current (Andreev-Bashkin) interspecies interactions. The Andreev-Bashkin coupling gives rise to a dissipationless drag (or entrainment) between the two superfluids. Within the quantum hydrodynamics approximation, we study the relations between speeds of sound, susceptibilities and static structure factors, in a generic model in which the density and spin dynamics decouple. Due to translational invariance, the density channel does not feel the drag. The spin channel, instead, does not satisfy the usual Bijl-Feynman relation, since the f-sum rule is not exhausted by the spin phonons. The very same effect on one dimensional Bose mixtures and their Luttinger liquid description is analysed within perturbation theory. Using diffusion quantum Monte Carlo simulations of a system of dipolar gases in a double layer configuration, we confirm the general results. Given the recent advances in measuring the counterflow instability, we also study the effect of the entrainment on the dynamical stability of a superfluid mixture with non-zero relative velocity.