Multiple period states of the superfluid Fermi gas in an optical lattice
Authors: Yoon S., Dalfovo F., Nakatsukasa T., Watanabe G.
Autors Affiliation: APCTP, Pohang 37673, Gyeongbuk, South Korea; KIAS, Quantum Universe Ctr, Seoul 02455, South Korea; Univ Trento, INO CNR BEC Ctr, I-38123 Povo, Italy; Univ Trento, Dept Phys, I-38123 Povo, Italy; Univ Tsukuba, Ctr Computat Sci, Tsukuba, Ibaraki 3058577, Japan; RIKEN Nishina Ctr, Wako, Saitama 3510198, Japan; POSTECH, Dept Phys, Pohang 37673, Gyeongbuk, South Korea; Inst for Basic Sci Korea, Ctr Theoret Phys Complex Syst, Daejeon 34051, South Korea; UST, 217 Gajeong Ro, Daejeon 34113, South Korea
Abstract: We study multiple period states of a two-component unpolarized superfluid Fermi gas in an optical lattice along the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate (BEC) crossover. The existence of states whose period is a multiple of the lattice spacing is a direct consequence of the nonlinear behavior of the gas, which is due to the presence of the order parameter associated with superfluidity. By solving Bogoliubov-de Gennes equations for a superfluid flow with finite quasimomentum, we find that, in the BCS side of the crossover, the multiple period states can be energetically favorable compared to the normal Bloch states and their survival time against dynamical instability drastically increases, suggesting that these states can be accessible in current experiments, in sharp contrast to the situation in BECs.
Journal/Review: NEW JOURNAL OF PHYSICS
Volume: 18 Pages from: 023011-1 to: 023011-10
KeyWords: BCS-BEC crossover; optical lattices; superfluidity; nonlinear phenomenaDOI: 10.1088/1367-2630/18/2/023011Citations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-10References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here