Multiple Period States of the Superfluid Fermi Gas in an Optical Lattice

International Conference on the Frontiers in Atomic, Molecular, and Optical Physics 2016

Watanabe, Gentaro^1,2 ; Yoon, Sukjin^3 ; Dalfovo, Franco^4 ; Nakatsukasa, Takashi^5,6

Department of Physics, Zhejiang Institute of Modern Physics, Zhejiang University, Hangzhou, Zhejiang

310027, China^1

Center for Theoretical Physics of Complex Systems, Institute for Basic Science (IBS), Daejeon

34051, Korea, Republic of^2

School of Computational Sciences, Korea Institute for Advanced Study (KIAS), Seoul

02455, Korea, Republic of^3

INO-CNR BEC Center and Department of Physics, University of Trento, Povo

38123, Italy^4

Center for Computational Sciences, University of Tsukuba, Tsukuba

305-8577, Japan^5

RIKEN Nishina Center, Wako, Saitama

351-0198, Japan^6

关键词: Bardeen-Cooper-Schrieffer;    Bogoliubov-de Gennes equations;    Bose-Einstein condensates;    Dynamical instabilities;    Sharp contrast;    Superfluid Fermi gas;    Superfluid flows;    Survival time;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/752/1/012002/pdf
DOI  :  10.1088/1742-6596/752/1/012002

来源: IOP

【 摘 要 】

We study multiple period states (i.e., states whose period is a multiple of the lattice constant) of a two-component unpolarized superfluid Fermi gas in an optical lattice along the crossover between the Bardeen-Cooper-Schrieffer (BCS) and Bose-Einstein condensate (BEC) states. 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. This is in sharp contrast to the situation in BECs.