Quantum kinetic theory of a Bose-Einstein gas confined in a lattice

• Autores: Rey, Ana Maria; Hu, B.L.; Calzetta, Esteban Adolfo; Clark, Charles W.
• Año de publicación: 2005
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Bose Einstein Condensates
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

We extend our earlier work on the nonequilibrium dynamics of a Bose-Einstein condensate initially loaded into a one-dimensional optical lattice. From the two-particle-irreducible (2PI) closed-time-path (CTP) effective action for the Bose-Hubbard Hamiltonian we derive causal equations of motion that treat mean-field effects and quantum fluctuations on an equal footing. We demonstrate that these equations reproduce well-known limits when simplifying approximations are introduced. For example, when the system dynamics admits two-time separation, we obtain the Kadanoff-Baym equations of quantum kinetic theory, and in the weakly interacting limit, we show that the local equilibrium solutions of our equations reproduce the second-order corrections to the self-energy of the type originally derived by Beliaev. The derivation of quantum kinetic equations from the 2PI-CTP effective action not only checks the viability of the formalism but also shows it to be a tractable framework for going beyond standard Boltzmann equations of motion.
Fil: Rey, Ana Maria. University of Maryland; Estados Unidos
Fil: Hu, B.L.. University of Maryland; Estados Unidos
Fil: Calzetta, Esteban Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina
Fil: Clark, Charles W.. National Institute Of Standards And Technology; Estados Unidos