A smeared quantum phase transition in disordered holography

TL;DR

This paper investigates how one-dimensional quenched disorder affects the quantum phase transition in a holographic Weyl semimetal, revealing smearing effects, rare region phenomena, and potential IR fixed points with discrete scale invariance.

Contribution

It introduces a holographic model to study disorder-induced smearing of quantum phase transitions and explores the interplay of disorder, temperature, and quantum criticality.

Findings

Disorder causes smearing of the quantum phase transition.

Rare regions with non-zero order parameter appear at the horizon.

Log-oscillatory structures suggest an IR fixed point with discrete scale invariance.

Abstract

We study the effects of quenched one-dimensional disorder on the holographic Weyl semimetal quantum phase transition (QPT), with a particular focus on the quantum critical region. We observe the smearing of the sharp QPT linked to the appearance of rare regions at the horizon where locally the order parameter is non-zero. We discuss the role of the disorder correlation and we compare our results to expectations from condensed matter theory at weak coupling. We analyze also the interplay of finite temperature and disorder. Within the quantum critical region we find indications for the presence of log-oscillatory structures in the order parameter hinting at the existence of an IR fixed point with discrete scale invariance.