Fermionic probes of local quantum criticality in one dimension

TL;DR

This paper investigates fermionic spectral functions in a 1+1D super Yang-Mills theory at finite density using holography, revealing Fermi points with finite relaxation times, contrasting with traditional Luttinger liquids.

Contribution

It demonstrates how fermionic correlators in 1+1D super Yang-Mills can be derived from higher-dimensional charged black hole models, highlighting new holographic connections.

Findings

Presence of quasi-particle peaks indicating Fermi points

Finite width of spectral features suggests non-trivial interactions

Fermionic correlators relate to charged AdS4 black hole results

Abstract

We study the spectral functions of fermionic operators in 1+1 dimensional SU(N) Super Yang-Mills theory with 16 supercharges at finite density using the holographically dual D1-brane geometry. This system exhibits quasi-particle peaks indicating the existence of Fermi points about which excitations have a finite relaxation time, in contrast with the Tomonaga-Luttinger model. The finite width may be attributed to the non-trivial interactions of the probe operators with the background density matrix, modeled holographically as a charged black hole. We show that the fermionic correlators can in fact be deduced from known results for fermion probes of the charged AdS4 black hole background, owing to some remarkable coincidences in supergravity truncations.