Excessive Noise as a Test for Many-Body Localization

TL;DR

This paper investigates many-body localization in insulators near the superconductor-insulator transition by measuring low-frequency noise, revealing a significant noise increase above a threshold voltage, supporting theoretical models.

Contribution

It provides experimental evidence linking low-frequency noise enhancement to many-body localization in disordered insulators.

Findings

Large noise increase at low temperatures above threshold voltage

Nonlinear conductivity correlates with noise enhancement

Results support theoretical models of many-body localization

Abstract

Recent experimental reports suggested the existence of a finite-temperature insulator in the vicinity of the superconductor-insulator transition. The rapid decay of conductivity over a narrow temperature range was theoretically linked to both a finite-temperature transition to a many-body-localized state, and to a charge-Berezinskii Kosterlitz Thouless transition. Here we report of low-frequency noise measurements of such insulators to test for many body localization. We observed a huge enhancement of the low-temperatures noise when exceeding a threshold voltage for nonlinear conductivity and discuss our results in light of the theoretical models.