Hawking Radiation and Non-equilibrium Quantum Critical Current Noise

TL;DR

This paper uses holography to study out-of-equilibrium quantum critical systems, revealing universal current noise behavior analogous to Hawking radiation, and provides a universal scaling function applicable across all field strengths.

Contribution

It demonstrates how holography can elucidate out-of-equilibrium universality in quantum critical systems, especially in current noise, connecting gravitational duals to quantum phenomena.

Findings

Derived a universal scaling function for current noise.

Showed out-of-equilibrium universality applies at all electric fields.

Linked current noise to Hawking radiation in gravity duals.

Abstract

The dynamical scaling of quantum critical systems in thermal equilibrium may be inherited in the driven steady-state, leading to universal out-of-equilibrium behaviour. This attractive notion has been demonstrated in just a few cases. We demonstrate how holography - a mapping between the quantum critical system and a gravity dual - provides an illuminating perspective and new results. Non-trivial out-of-equilibrium universality is particularly apparent in current noise, which is dual to Hawking radiation in the gravitational system. We calculate this in a 2-dimensional system driven by a strong in-plane electric field and deduce a universal scaling function interpolating between previously established equilibrium and far-from-equilibrium current noise. Since this applies at all fields, out-of-equilibrium experiments no longer require very high fields for comparison with theory.