Collisionless dynamics of the condensate predicted in the random phase approximation

摘要: From the microscopic theory, we derive a number conserving quantum kinetic equation, for dilute Bose gas valid at any temperature, in which binary collisions between quasi-particles are mediated by Bogoliubov collective excitations. This different approach starts from many-body Hamiltonian of Boson and uses, an appropriate way, generalized random phase approximation. As result, collision term equation contains higher order contributions expansion interaction parameter. The major interest this particular mechanism is that, regime where condensate stable, process condensed noncondensed particles totally blocked due to total annihilation mutual potential induced itself. consequence, not constrained relax can be superfluid. Furthermore, Boltzmann-like H-theorem entropy exists allows distinguish dissipative nondissipative phenomena (like vortices). We also illustrate analogy theory plasma, excitations correspond precisely plasmon. spectrum these their damping exactly ones obtained gapless equilibrium dielectric formalism developed Fliesser et al. [Phys. Rev. A 64 (2001) 013609]. Finally, recover results ground state energy particle momentum distribution. work more details summary presented Navez [J. Low Temp. Phys., 138 (2005) 705–710].