Ran Qi, Zhe-Yu Shi, Hui Zhai
It is known from the solution of two-body problem that an anisotropic dipolar interaction can give rise to s-wave scattering resonances, which are named as dipolar interaction induced resonaces (DIIR). In this letter, we study zero-temperature many-body physics of a two-component Fermi gas across a DIIR. In the regime with small $k_{\text{F}}D$, where $k_{\text{F}}$ is the Fermi momentum and $D$ is dipolar length, we show that despite of the anisotropic nature of dipolar interaction, the resulting pairing order parameter is a nearly isotropic singlet pairing and the physics can be well described by an s-wave resonant interaction potential with finite range corrections. The pairing energy is as strong as a unitary Fermi gas nearby a magnetic Feshbach resonance. In the regime with large $k_{\text{F}}D$, the anisotropic effect plays an important role. We find phase transitions from singlet paring to a state with mixed singlet and triplet pairing, and then from mixed pairing to pure triplet pairing. The state with mixed pairing spontaneously breaks the time-reversal symmetry.
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http://arxiv.org/abs/1208.5419
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