Quasi-particle properties and Cooper pairing in trapped Fermi gases

TL;DR

This paper investigates how density and spin fluctuations influence quasi-particle properties and pairing interactions in a finite, trapped Fermi gas, providing insights relevant to many-body physics in atomic nuclei and neutron stars.

Contribution

It presents a calculation of quasi-particle effective mass, lifetime, and pairing interactions in a finite trapped Fermi gas, extending many-body physics understanding to small systems.

Findings

Effective mass and lifetime of quasi-particles are influenced by density and spin fluctuations.

The pairing interaction affects the BCS critical temperature in finite Fermi gases.

Insights are applicable to systems like atomic nuclei and neutron stars.

Abstract

The possibility for the particles in a Fermi gas to emit and reabsorb density and spin fluctuations gives rise to an effective mass and to a lifetime of the quasi-particles, as well as to an effective pairing interaction which affect in an important way the BCS critical temperature. We calculate these effects for a spherically symmetric trapped Fermi gas of $\sim$ 1000 particles. The calculation provides insight on the many-body physics of finite Fermi gases and is closely related to similar problems recently considered in the case of atomic nuclei and neutron stars.