Spin Correlation and Superfluidity of Trapped Fermi Atoms on an Optical Lattice
- CCSE, Japan Atomic Energy Agency, 6-9-3 Higashi-Ueno, Taito-ku, Tokyo 1100-0015 (Japan) and CREST(JST), 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)
- CCSE, Japan Atomic Energy Agency, 6-9-3 Higashi-Ueno, Taito-ku, Tokyo 1100-0015 (Japan)
- Institute of Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 (Japan)
We investigate a possibility of superfluidity in a trapped gas of Fermi atoms with repulsive interaction U in the presence of an optical lattice. Applying the exact diagonalization method to a one-dimensional fermion-Hubbard model including the trap potential, we find that, when U exceeds a critical value, the binding energy of two Fermi atoms becomes negative indicating that an attractive interaction effectively works. In this case, a 'Mott core' appears in the trap center, where each site is occupied by one atom, and a large Cooper-pair amplitude develops between atoms in the left and right hand sides of this core. In order to clarify the origin of the attractive force, we compute a pseudo spin correlation between neighboring sites given by <Si{center_dot}Si+1>. As a result, we find that a creation of a singlet pair between both sides of the Mott core is strongly coupled with a pseudo-spin singlet re-formation leading to an energy gain process.
- OSTI ID:
- 20884857
- Journal Information:
- AIP Conference Proceedings, Vol. 850, Issue 1; Conference: LT24: 24. international conference on low temperature physics, Orlando, FL (United States), 10-17 Aug 2005; Other Information: DOI: 10.1063/1.2354607; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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