19 July 2010 to 27 August 2010
Nordita
Europe/Stockholm timezone

Watanabe, Gentaro: Superfluid unitary Fermi gases in a 1D optical lattice --- thermodynamic properties and critical velocity

3 Aug 2010, 11:00
1h
Nordita

Nordita

Description

A recent experiment with Fermi superfluids in one-dimensional (1D) optical lattices has revealed that superfluidity is particularly robust at unitarity [1]. Motivated by this experiment, we study the effects of a 1D optical lattice on the thermodynamic properties [2] and on the critical velocity for the Landau (energetic) instability [3] of superfluid unitary Fermi gases. We show that, the inclusion of a 1D optical lattice, by favoring the formation of molecular configurations and by inducing a band structure in the quasiparticle spectrum, has profound consequences on the thermodynamic quantities, the density profile, and the collective oscillations of the unitary Fermi gas [2]. Regarding the Landau critical velocity, we have derived an analytical expression, which is applicable for both bosonic and fermionic superfluids in hydrodynamic regime flowing through any shape of the external potential [3]. We also find that the behavior of the critical velocity in the presence of a periodic potential is very different from that of a single barrier [3]. In the last part of this presentation, our recent results about the loop structure of the energy band of superfluid Fermi gases are also given. References: [1] D. E. Miller et al., Phys. Rev. Lett. 99, 070402 (2007). [2] GW, Orso, Dalfovo, Pitaevskii, and Stringari, Phys. Rev. A 78, 063619 (2008). [3] GW, Dalfovo, Piazza, Pitaevskii, and Stringari, Phys. Rev. A 80, 053602 (2009).

Primary author

Dr Gentaro Watanabe (Asia Pacific Center for Theoretical Physics)

Presentation materials