Energy and structure of dilute hard- and soft-sphere gases


Autoria(s): Mazzanti, F.; Polls Martí, Artur; Fabrocini, A.
Contribuinte(s)

Universitat de Barcelona

Data(s)

04/05/2010

Resumo

The energy and structure of dilute hard- and soft-sphere Bose gases are systematically studied in the framework of several many-body approaches, such as the variational correlated theory, the Bogoliubov model, and the uniform limit approximation, valid in the weak-interaction regime. When possible, the results are compared with the exact diffusion Monte Carlo ones. Jastrow-type correlation provides a good description of the systems, both hard- and soft-spheres, if the hypernetted chain energy functional is freely minimized and the resulting Euler equation is solved. The study of the soft-sphere potentials confirms the appearance of a dependence of the energy on the shape of the potential at gas paremeter values of x~0.001. For quantities other than the energy, such as the radial distribution functions and the momentum distributions, the dependence appears at any value of x. The occurrence of a maximum in the radial distribution function, in the momentum distribution, and in the excitation spectrum is a natural effect of the correlations when x increases. The asymptotic behaviors of the functions characterizing the structure of the systems are also investigated. The uniform limit approach is very easy to implement and provides a good description of the soft-sphere gas. Its reliability improves when the interaction weakens.

Identificador

http://hdl.handle.net/2445/9573

Idioma(s)

eng

Publicador

The American Physical Society

Direitos

(c) The American Physical Society, 2003

info:eu-repo/semantics/openAccess

Palavras-Chave #Matèria condensada tova #Estadística quàntica #Mecànica estadística #Gas de Bose-Einstein #Soft condensed matter #Quantum statistics #Statistical mechanics #Bose-Einstein gas
Tipo

info:eu-repo/semantics/article