Fermi Surface Resonance and Quantum Criticality in Strongly Interacting Fermi Gases

TL;DR

This paper predicts a new quantum critical phase called Fermi surface resonance in strongly interacting Fermi gases, characterized by unique spectral and transport properties, and suggests it can be observed in semiconductor heterostructures.

Contribution

It introduces the concept of Fermi surface resonance as a novel quantum phase arising from strong interactions and specific Fermi surface conditions.

Findings

Identification of a quantum critical phase with power-law spectral density

Divergent static susceptibilities indicating criticality

Anomalous temperature dependence of resistivity similar to strange metals

Abstract

Fermions in the Fermi gas obey the Pauli exclusion principle restricting any two fermions from filling the same quantum state. Strong interaction between fermions can completely change the properties of the Fermi gas. In our theoretical study we find a new exotic quantum phase in strongly interacting Fermi gases constrained to a certain condition imposed on the Fermi surfaces which we call the Fermi surface resonance. The new phase is quantum critical which can be identified by the power-law frequency tail of the spectral density and divergent static susceptibilities. An especially striking feature of the new phase is the anomalous power-law temperature dependence of the dc resistivity that is similar to strange metals. The new quantum critical phase can be experimentally found in ordinary semiconductor heterostructures.