Quantum criticality of a Fermi gas with a spherical dispersion minimum

TL;DR

This paper investigates the quantum phase transition in a Fermi gas with a spherical dispersion minimum, focusing on universal interactions and implications for fermionic superfluids with unequal densities.

Contribution

It introduces a theoretical framework for the quantum criticality of Fermi gases with spherical minima, highlighting universal interactions near the critical point.

Findings

Identifies the nature of the quantum phase transition at the spherical dispersion minimum.

Describes universal quasiparticle interactions controlling physical properties.

Discusses implications for fermionic superfluids with density imbalance.

Abstract

We describe the quantum phase transition of a Fermi gas occurring when the quasiparticle excitation energy has a minimum in momentum space which crosses zero on a sphere of radius k_0 \neq 0. The quasiparticles have a universal interaction which controls the physical properties in vicinity of the quantum critical point. We discuss applications to fermionic superfluids formed by pairing two fermion species, near the point where the densities of the two species become unequal.