Landau Damping of Collective Modes in a Disc-Shaped Bose--Einstein Condensate

We investigate the Landau damping of collective modes in an anisotropic Bose--Einstein condensate (BEC). Based on divergence-free analytical solutions for the ground state wavefunction of the condensate and all eigenvalues and eigenfunctions for thermal excited quasiparticles, we make a detailed analytical calculation on coupling matrix elements. We evaluate the Landau damping of a quadrupole collective mode in the BEC with a disc-shaped trap and discuss its dependence on temperature and particle number of the system.