Journal of Atomic and Molecular Physics
Landau damping and frequency-shift of a monopole mode in a spherical rubidium Bose-Einstein condensate
Sheng Peng
Abstract
The Landau damping and frequency- shift of a monopole mode in a spherical rubidium Bose- Einstein condensate are investigated by using the Hartree- Fock- Bogoliubov approximation. The damping rate and frequency- shift magnitude and their temperature dependence are analytically calculated by using the parameters of particle number and traping frequency in the study of numerical simulation and experiment in existence. In the calculation,the practical relaxations of the elementary excitations and the orthometric relation among them are taken into account to obtain the calculation formula for damping and frequency- shift,and the first approximation of Gaussian distribution function is employed for the ground- state wavefunction to eliminate the divergence of the three- mode coupling matrix elements. Our calculation results are directly and indirectly compared with the numerical simulation ones and experimental ones,respectively. And all the comparison illustrate that our method is reasonable.