Anisotropic destruction of the Fermi surface in inhomogeneous holographic lattices

TL;DR

This paper investigates how inhomogeneous lattice-like potentials affect the fermionic spectral function in strongly correlated holographic systems, revealing anisotropic Fermi surface deformation and broadening of quasiparticles due to horizon anisotropy.

Contribution

It demonstrates that anisotropic Fermi surface deformation in holographic matter arises from horizon anisotropy rather than periodic potential effects, providing new insights into strongly correlated critical systems.

Findings

Fermi surface exhibits umklapp gaps at small wave vectors.

Large wave vectors cause anisotropic deformation and broadening of quasiparticles.

Anisotropic effects are linked to horizon properties, not lattice periodicity.

Abstract

We analyze fermionic response of strongly correlated holographic matter in presence of inhomogeneous periodically modulated potential mimicking the crystal lattice. The modulation is sourced by a scalar operator that explicitly breaks the translational symmetry in one direction. We compute the fermion spectral function and show that it either exhibits a well defined Fermi surface with umklapp gaps opening on the Brillouin zone boundary at small lattice wave vector, or, when the wave vector is large, the Fermi surface is anisotropically deformed and the quasiparticles get significantly broadened in the direction of translation symmetry breaking. Making use of the ability of our model to smoothly extrapolate to the homogeneous Q-lattice like setup, we show that this novel effect is not due to the periodic modulation of the potential and Umklapp physics, but rather due to the anisotropic features of the holographic horizon. That means it encodes novel physics of strongly correlated critical systems which may be relevant for phenomenology of exotic states of electron matter.