2001/06/25 by Bernhard Hikaru Valtan, Munehiro Nishida, Susumu Kurihara
Physics and Astronomy · #cond-mat.soft
published as Laser Physics, 12, 217 (2002) · 5 pages,3 figures
arxiv created 2001/06/25 · arxiv updated 2009/11/30
Using the effective action formalism, we investigate collective excitations of a dilute mixture of a Bose gas and a two component Fermi gas when both bosons and fermions have undergone superfluid transitions. We show that there is a repulsion between Bogoliubov and Anderson modes, which has important implications including disappearance of boson superfluidity. We derive an analytic expression for the long-wavelength dispersion relation of the mixture at zero temperature and give a condition for the instability. We also numerically calculate the damping rate due to boson-fermion interaction at finite temperatures and show that the two modes are stable at sufficiently low temperatures.