# Relaxation of Fermionic Excitations in a Strongly Attractive Fermi Gas in an Optical Lattice

 Title: Relaxation of Fermionic Excitations in a Strongly Attractive Fermi Gas in an Optical Lattice Author: Sensarma, Rajdeep; Pekker, David; Demler, Eugene A.; Lukin, Mikhail D.; Rey, Ana Maria Note: Order does not necessarily reflect citation order of authors. Citation: Sensarma, Rajdeep, David Pekker, Ana Maria Rey, Mikhail D. Lukin, and Eugene A. Demler. 2011. Relaxation of fermionic excitations in a strongly attractive fermi gas in an optical lattice. Physical Review Letters 107(14): 145303. Full Text & Related Files: 1105.1778v1.pdf (371.4Kb; PDF) Abstract: We theoretically study the relaxation of high energy single particle excitations into molecules in a system of attractive fermions in an optical lattice, both in the superfluid and the normal phase. In a system characterized by an interaction scale $$U$$ and a tunneling rate $$t$$, we show that the relaxation rate scales as $$\sim Ct\exp⁡[-\alpha U^2/t^2\ln⁡(U/t)]$$ in the large $$U/t$$ limit. We obtain explicit expressions for the temperature and density dependent exponent $$\alpha$$, both in the low temperature superfluid phase and the high temperature phase with pairing but no coherence between the molecules. We find that the relaxation rate decreases both with temperature and deviation of the fermion density from half filling. We show that quasiparticle and phase degrees of freedom are effectively decoupled within experimental time scales allowing for observation of ordered states even at high total energy of the system. Published Version: doi:10.1103/PhysRevLett.107.145303 Other Sources: http://arxiv.org/abs/1105.1778 Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:8254599 Downloads of this work: