Specific heat and effects of uniaxial anisotropy of a p-wave pairing interaction in a strongly interacting ultracold fermi gas

We investigate the specific heat C_V at constant volume and effects of uniaxial anisotropy of a p-wave attractive interaction in the normal state of an ultracold Fermi gas. Within the framework of the strong-coupling theory developed by Nozières and Schmitt-Rink, we evaluate this thermodynamic quantity as a function of temperature, in the whole interaction regime. While the uniaxial anisotropy is not crucial for C_V in the weak-coupling regime, C_V is found to be sensitive to the uniaxial anisotropy in the strong-coupling regime. This originates from the population imbalance among p_i-wave molecules (i = x, y, z), indicating that the specific heat is a useful observable to see which kinds of p-wave molecules dominantly exist in the strong-coupling regime when the p-wave interaction has uniaxial anisotropy. Using this strong point, we classify the strong-coupling regime into some characteristic regions. Since a p-wave pairing interaction with uniaxial anisotropy has been discovered in a ⁴⁰K Fermi gas, our results would be useful in considering strong-coupling properties of a p-wave interacting Fermi gas, when the interaction is uniaxially anisotropic.