Abstract:

Ultracold, trapped quantum gases have gained prominence  in recent years as systems where fundamental theories of many-body  physics can be tested in a clean environment with "tunable"  parameters.  One of the most exciting prospects is the possibility  of observing second sound in a strongly interacting Fermi gas  superfluid.  Never found (so far) outside quantum liquids, second  sound is a pure temperature wave: a collective hydrodynamic mode  that has no analogue in classical, non-superfluid liquids.  Naturally, this
mode is quite different in trapped Fermi gases than in liquid  Helium. In this talk, I discuss the nature
of second sound in these gases and outline a new scheme to excite  and detect these modes.

Ref.: E. Taylor, H. Hu, X.-J. Liu, L. P. Pitaevskii, A. Griffin,  and S. Stringari, arXiv:0905.0257