A Non-Fermi Liquid from a Charged Black Hole; A Critical Fermi Ball

TL;DR

This paper uses AdS/CFT correspondence to analyze a 2+1D non-relativistic quantum field theory, revealing a critical Fermi ball with no quasiparticle peaks but a well-defined Fermi surface.

Contribution

It introduces the concept of a critical Fermi ball in a holographic setting, showing a new type of non-Fermi liquid behavior with critical modes inside the Fermi surface.

Findings

No quasiparticle peaks in spectral function

Presence of a well-defined Fermi surface

Existence of a critical Fermi ball with gapless modes

Abstract

Using the AdS/CFT correspondence, we calculate a fermionic spectral function in a 2+1 dimensional non-relativistic quantum field theory which is dual to a gravitational theory in the $AdS_4$ background with a charged black hole. The spectral function shows no quasiparticle peak but the Fermi surface is still well defined. Interestingly, all momentum points inside the Fermi surface are critical and the gapless modes are defined in a {\it critical Fermi ball} in the momentum space.