Abstract
Critical velocities of superfluid Fermi gases in optical lattices are theoretically investigated across the BCS-BEC crossover. We calculate the excitation spectra in the presence of a superfluid flow in one- and two-dimensional optical lattices. It is found that the spectrum of low-lying Anderson-Bogoliubov (AB) mode exhibits a roton-like structure in the short-wavelength region due to the strong charge density wave fluctuations, and with increasing the superfluid velocity one of the roton-like minima reaches zero before the single-particle spectrum does. This means that superfluid Fermi gases in optical lattices are destabilized due to spontaneous emission of the roton-like AB mode instead of due to Cooper pair breaking.
| Original language | English |
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| Title of host publication | Proceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008 |
| Publisher | World Scientific Publishing Co. Pte Ltd |
| Pages | 41-44 |
| Number of pages | 4 |
| ISBN (Print) | 981428212X, 9789814282123 |
| Publication status | Published - 2009 |
| Event | 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008 - Hatoyama, Saitama Duration: 2008 Aug 25 → 2008 Aug 28 |
Other
| Other | 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008 |
|---|---|
| City | Hatoyama, Saitama |
| Period | 08/8/25 → 08/8/28 |
Keywords
- Anderson-Bogoliubov mode
- Critical velocity
- Superfluidity
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics