1204.6476 (Wei Yi et al.)

Molecule and polaron in a highly polarized two-dimensional Fermi gas
with spin-orbit coupling    [PDF]

Wei Yi, Wei Zhang

We show that spin-orbit coupling (SOC) gives rise to a pairing instability in a highly polarized two-dimensional Fermi gas for arbitrary interaction strength. In the weak-coupling limit, the pairing instability leads to a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-like molecular state, which undergoes first-order transition into conventional pairing state when the SOC increases or when the interaction is tuned stronger. These pairing states are meta-stable against a polaron state dressed by particle-hole fluctuations for small SOC. At large SOC, a polaron-molecule transition exists, which suggests a phase transition between the topological superfluid state and the normal state in a highly polarized Fermi gas. These findings may be tested directly in future experiments.

View original: http://arxiv.org/abs/1204.6476