Estimation of the condensate fraction from the static structure factor
We present an analytical method to estimate the condensate fraction n0/n in strongly correlated systems for which the zero-temperature static structure factor S(p) is known. The advantage of the proposed method is that it allows us to predict the long-range behavior of the one-body density matrix (i...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| 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:2117/353451 |
| Acceso en línea: | https://hdl.handle.net/2117/353451 https://dx.doi.org/10.1103/PhysRevB.103.094511 |
| Access Level: | acceso abierto |
| Palabra clave: | Superfluidity Bose-Einstein condensation Monte Carlo method Superfluid density Bose-Einstein condensates Quantum Monte-Carlo Superfluïdesa Condensació de Bose-Einstein Montecarlo, Mètode de Àrees temàtiques de la UPC::Física |
| Sumario: | We present an analytical method to estimate the condensate fraction n0/n in strongly correlated systems for which the zero-temperature static structure factor S(p) is known. The advantage of the proposed method is that it allows us to predict the long-range behavior of the one-body density matrix (i) in macroscopic and mesoscopic systems, (ii) in three- and two-dimensional geometry, (iii) at zero and low finite temperature, and (iv) in weakly and strongly correlated regimes. Our method is tested against exact values obtained with various quantum Monte Carlo methods in a number of strongly correlated systems showing an excellent agreement. The proposed technique is also useful in numerical simulations as it allows us to extrapolate the condensate fraction to the thermodynamic limit for particle numbers as small as tens to hundreds. Our method is especially valuable for extracting the condensate fraction from the experimentally measured static structure factor S(p), thus providing a simple alternative technique for the estimation of n0/n. We analyze available experimental data for S(p) of superfluid helium and find an excellent agreement with the experimental value of n0/n. |
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