1307.5716 (Arko Roy et al.)

Additional Goldstone mode and finite temperature effects in strongly
phase-separated heteronuclear binary condensates    [PDF]

Arko Roy, S. Gautam, D. Angom

We examine the Goldstone or zero energy modes of the quasi-1D binary condensate of Rb and Cs at T=0 as a function of the interspecies interaction. At phase-separation, an additional Goldstone mode appears in the system and persists at higher interspecies interaction for symmetric density profiles. This is not the case for binary condensates with asymmetric profiles. We, then, study evolution of the modes at $T\neq0$ using the Hartree-Fock-Bogoliubov theory with Popov approximation. There is mode bifurcation close to the critical temperature, however, the Kohn mode shows deviation from the natural frequency. This is on account of the higher overlap between the thermal and condensate clouds, particularly at the interface in phase-separated domain.

View original: http://arxiv.org/abs/1307.5716