Holography and ARPES sum-rules

TL;DR

This paper modifies the holographic approach to better model fermionic single-particle excitations in strongly interacting theories, ensuring ARPES sum-rule compliance, and applies it to Lifshitz-invariant conformal field theories.

Contribution

It introduces a new holographic prescription with a dynamical fermionic source to produce correlators obeying ARPES sum-rules, applicable to Lifshitz and relativistic theories.

Findings

Correlators can be made to obey ARPES sum-rules with the modified prescription.

The approach is applicable to Lifshitz theories with arbitrary dynamical exponent z.

The method bridges holography and ARPES phenomenology in strongly correlated systems.

Abstract

We study correlation functions of elementary fermions in strongly interacting field theories using the AdS/CFT correspondence. This correspondence generically associates bulk fields to composite operators in field theory. We modify the holographic prescription in order to obtain correlators that correspond to fermonic single-particle excitations by introducing a dynamical fermionic source localized on a UV brane in a holographic background. We work out the conditions when these correlators obey the zeroth frequency sum-rule satisfied by angle-resolved photo-emission spectroscopy (ARPES) and are thus directly relevant to the AdS/CMT correspondence. To illustrate our techniques, we study field theories at zero chemical potential with an arbitrary dynamical exponent z, i.e., the Lifshitz invariant conformal field theories, including the usual relativistic case z=1.