Anomalous Noise in the Pseudogap Regime of YBa$_2$Cu$_3$O$_{7-\delta}$

TL;DR

This paper reports the discovery of anomalous noise in underdoped YBCO films near 250 K, suggesting a symmetry-breaking electronic state possibly related to fluctuating charge nematic order.

Contribution

It identifies a new noise regime with features indicating a collective electronic state, proposing a possible charge nematic order in the pseudogap phase of YBCO.

Findings

Unusual noise observed below 250 K in YBCO and Ca-YBCO films.

Features include large fluctuators, magnetic sensitivity, and aging effects.

Supports the interpretation of fluctuating charge nematic order.

Abstract

An unusual noise component is found near and below about 250 K in the normal state of underdoped YBCO and Ca-YBCO films. This noise regime, unlike the more typical noise above 250 K, has features expected for a symmetry-breaking collective electronic state. These include large individual fluctuators, a magnetic sensitivity, and aging effects. A possible interpretation in terms of fluctuating charge nematic order is presented.