Strong-Coupling and Finite Temperature Effects on $p$-wave Contacts

TL;DR

This paper explores how strong interactions and finite temperatures influence p-wave contacts and momentum distribution in a Fermi gas, revealing non-monotonic behaviors and additional terms beyond traditional models, with implications for experimental observations.

Contribution

The study introduces a strong-coupling theoretical framework to analyze p-wave contacts and momentum distribution, highlighting non-monotonic interaction dependence and extra contributions in the asymptotic behavior.

Findings

p-wave contacts increase monotonically with interaction strength

effective range causes non-monotonic dependence and sign change

extra terms dominate large-momentum behavior at high temperatures

Abstract

We theoretically investigate strong-coupling and finite temperature effects on the p-wave contacts, as well as the asymptotic behavior of the momentum distribution in large momentum region in a one-component Fermi gas with a tunable p-wave interaction. Including p-wave pairing fluctuations within a strong-coupling theory, we calculate the p-wave contacts above the superfluid transition temperature $T_{\rm c}$ from the adiabatic energy relations. We show that while the p-wave contacts related to the scattering volume monotonically increases with increasing the interaction strength, one related to the effective range non-monotonically depends on interaction strength and its sign changes in the intermediate-coupling regime. The non-monotonic interaction dependence of these quantities is shown to originate from the competition between the increase of the cutoff momentum and the decrease of the coupling constant of the p-wave interaction with increasing the effective range. We also analyze the asymptotic form of the momentum distribution in large momentum region. In contrast to the conventional s-wave case, we show that the asymptotic behavior cannot be completely described by only the p-wave contacts, and the extra terms, which is not related to the thermodynamic properties, appear. Furthermore, in high temperature region, we find that the extra terms dominate the sub-leading term of the large-momentum distribution. We also directly compare our results with the recent experimental measurement, by including the effects of a harmonic trap potential within the local density approximation. We show that our model explains the dependence on the interaction strength of the p-wave contacts.