Bose polarons at finite temperature and strong coupling
A mobile impurity coupled to a weakly interacting Bose gas, a Bose polaron, displays several interesting effects. While a single attractive quasiparticle is known to exist at zero temperature, we show here that the spectrum splits into two quasiparticles at finite temperatures for sufficiently stron...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2018 |
| 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:2117/116050 |
| Acceso en línea: | https://hdl.handle.net/2117/116050 https://dx.doi.org/10.1103/PhysRevLett.120.050405 |
| Access Level: | acceso abierto |
| Palabra clave: | Quantum theory Bose-Einstein condensates Bose-Fermi mixtures Mixtures of atomic and/or molecular quantum gases Polarons Quàntums, Teoria dels Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Telecomunicació òptica::Fotònica |
| Sumario: | A mobile impurity coupled to a weakly interacting Bose gas, a Bose polaron, displays several interesting effects. While a single attractive quasiparticle is known to exist at zero temperature, we show here that the spectrum splits into two quasiparticles at finite temperatures for sufficiently strong impurity-boson interaction. The ground state quasiparticle has minimum energy at Tc, the critical temperature for Bose-Einstein condensation, and it becomes overdamped when T»Tc. The quasiparticle with higher energy instead exists only below Tc, since it is a strong mixture of the impurity with thermally excited collective Bogoliubov modes. This phenomenology is not restricted to ultracold gases, but should occur whenever a mobile impurity is coupled to a medium featuring a gapless bosonic mode with a large population for finite temperature. |
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