Studies of a single component Fermi gas near a p-wave resonance with the lowest order constrained variational method

Abstract

We study a single component Fermi gas near a p-wave resonance with the lowest order constrained variational (LOCV) method. We obtain the energy per particle for the ground state of single component Fermi gas near a p-wave resonance with LOCV method. We also calculate compressibility of the single component Fermi gas near a p-wave resonance and it shows that in the strongly interacting BCS side, the system would lose its stability and collapse. The width of unstable region is proportional to Fermi energy which reflects the universality of dilute Fermi gas. The two p-wave contacts are also obtained and their variation tendencies with the interaction strength are qualitatively in agreement with recent experimental results.

The universalities of a single-component Fermi gas at a p-wave resonant point

“…Then, the continuity condition at r = d, the normalization condition, eq. ( 4), and the eigenequation (5) can be solved self-consistently to obtain the ground-state energy per particle for a single-component Fermi gas [32]. The energy obtained with the LOCV method near the p-wave resonance is also similar with the energy result obtained from other methods [33,34,36].…”

“…This universal constant is also very similar to the Bertsch parameter in the s-wave case. In this letter, with the lowest-order constrained variational method (LOCV) [28][29][30][31] adopted in the p-wave case [32], we examine the energy per particle at the p-wave resonant point and find that this universal constant a is about 0.0245. What is more, we also calculate the density dependence of the energy per particle at the resonant point and find that our result shows a n 2/3 density dependence which is different from an earlier work which claims a linear density dependence [33,34].…”

“…In our earlier work, we have extended the lowest-order constrained variational (LOCV) method [29][30][31] to the single-component p-wave Fermi gas case [32]. Here we just give a brief explanation of this method.…”