Kinetic properties of a Bose-Einstein gas at finite temperature
Year: 1998
Authors: Lopez-Arias T., Smerzi A.
Autors Affiliation: International School of Advanced Studies, Trieste, I-34014, Via Beirut 2/4, Italy
Abstract: We study, in the framework of the Boltzmann-Bloch-Nordheim equation (BBN)I the kinetic properties of a boson gas above the Bose-Einstein transition temperature T-c. The BBN equation is solved numerically within an algorithm that we test with exact analytical results for the collision rate of a homogeneous system in thermal equilibrium. In the classical regime (T much greater than T-c), the relaxation time of a quadrupolar deformation in momentum space is proportional to the mean free collision time tau(relax)(proportional to)tau(coll)(proportional to)T(-1/2). Approaching the critical temperature, quantum statistic effects become dominant, and the collision rate increases dramatically. Nevertheless, this does not affect the relaxation properties of the gas that depend only on the spontaneous collision term in BBN. The relaxation time becomes tau(relax)(proportional to)(T – T-c)(-1/2), exhibiting a critical slowing down. These phenomena can be experimentally confirmed looking at the damping properties of collective motions induced on trapped atoms. The possibility to observe a transition from collisionless (zero-sound) to hydrodynamic (such as first and second-sound) is finally discussed.
Journal/Review: PHYSICAL REVIEW A
Volume: 58 (1) Pages from: 526 to: 530
KeyWords: Heavy-ion Collisions; Collective Excitations; Condensed Gas; SaturationDOI: 10.1103/PhysRevA.58.526Citations: 15data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-20References taken from IsiWeb of Knowledge: (subscribers only)