Dipolar interaction enhanced Fulde-Ferrell-Larkin-Ovchinnikov state
Hao Lee1,2,4*, S. I. Matveenko3,4, Daw-Wei Wang1,2, G. V. Shlyapnikov4,5
1Physics department, National Tsing Hua University, Hsinchu 30013, Taiwan
2Physics Division, National Center for Theoretical Sciences, Hsinchu 30013, Taiwan
3Landau Institute for Theoretical Physics, Russian Academy of Sciences, Moscow, Russian Federation
4LPTMS, Universite Paris-Sud, CNRS, 91405 Orsay, France
5Van der Waals-Zeeman Institute, University of Amsterdam, Valckenierstraat 65/67, 1018 XE Amsterdam, Netherlands
* presenting author:Hao Lee, email:h.b.rocker.lee@gmail.com
We investigate both analytically and numerically the ground state and finite temperature phase diagram of population imbalanced fermionic polar molecules loaded in a bilayer system. When the imbalance is larger than a critical value, the ground state has a first order transition to a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state with a triangular lattice structure, which is stabilized by the long-ranged inter-layer interaction and exists in a much larger parameter regime than the short-ranged case. When temperature is increased from zero, the tri-critical temperature (T*c) is found to be as high as 0.95T0c, where T0c is the critical temperature without population imbalanced. Our results demonstrate that a long-ranged attractive inter-layer interaction can be an important factor to stabilize the FFLO state and to make experimental observation possible.

Keywords: ultracold , superfluid, BCS, FFLO, molecule