Chiral 2D "Strange Metals" from N = 4 SYM

TL;DR

This paper explores a novel chiral 1+1 dimensional sector in N=4 SYM, revealing unusual fermionic phases and their gravity duals, contributing to understanding of strange metals and black hole microstates.

Contribution

It identifies a chiral 1+1D sector governing fluctuations around fermionic Fermi surfaces in N=4 SYM, linking field theory results to black hole near horizon excitations.

Findings

Fluctuations are governed by a chiral 1+1D coset CFT.

Ground states are Fermi surface operators in the fermionic su(1,1) sector.

Gravity duals involve near horizon black hole degenerations.

Abstract

Familiar field theories may contain closed subsectors made out of only fermions, which can be used to explore new and unusual phases of matter in lower dimensions. We focus on the fermionic su(1,1) sector in N=4 SYM and on its ground states, which are Fermi surface states/operators. By computing their spectrum to order $(g_{YM}^2 N)^2$, we argue that fluctuations around this fermi surface, within the sector and in the limit $k_F\rightarrow\infty$, are governed by a chiral 1+1 dimensional sector of the "strange metal" coset $SU(N)_N \otimes SU(N)_N/SU(N)_{2N}$. On the gravity side, the conjectured dual configuration is an $S=0$ degeneration of a rotating black hole. On general grounds we expect that the near horizon excitations of $(S=0,\Omega=1,J\rightarrow\infty)$ degenerations of black holes will be governed by a chiral sector of a 1+1 CFT.