Superfluid fraction of interacting bosonic gases
The superfluid fraction f of a quantum fluid is defined in terms of the response of the system to a weak and constant drag. Notably, Leggett long ago derived two simple expressions providing a rigorous upper bound and a heuristic lower bound for f. Here we study the superfluid fraction of bosonic ga...
| Autores: | , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2025 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositório: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglês |
| OAI Identifier: | oai:upcommons.upc.edu:2117/425010 |
| Acesso em linha: | https://hdl.handle.net/2117/425010 https://dx.doi.org/10.1103/PhysRevA.111.L011302 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Bose gases Bose-Einstein condensates Cold and ultracold molecules Cold atoms & matter waves Cold gases in optical lattices Àrees temàtiques de la UPC::Física |
| Resumo: | The superfluid fraction f of a quantum fluid is defined in terms of the response of the system to a weak and constant drag. Notably, Leggett long ago derived two simple expressions providing a rigorous upper bound and a heuristic lower bound for f. Here we study the superfluid fraction of bosonic gases in various two-dimensional potentials, such as regular optical lattices and disordered speckles, by solving the Gross-Pitaevskii equation and performing Diffusion Monte Carlo simulations. We show that under conditions relevant for most ultracold experiments the bounds proposed by Leggett provide a surprisingly narrow bracketing of the exact value of the superfluid fraction. |
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