A Novel Dielectric Anomaly in Cuprates and Nickelates: Signature of an Electronic Glassy State

TL;DR

This paper reports a dielectric anomaly in cuprates and nickelates indicating the presence of an electronic glassy state, characterized by a large dielectric constant and universal scaling behavior, revealing a common charge glass phase in these materials.

Contribution

It uncovers a universal dielectric response and evidence of an electronic glassy state in hole-doped cuprates and nickelates, a novel insight into their charge dynamics.

Findings

Large dielectric constant at high temperature

Step-like drop in dielectric constant at low temperature

Universal scaling in Cole-Cole plots

Abstract

The low-frequency dielectric response of hole-doped insulators La_{2}Cu_{1-x}Li_{x}O_{4} and La_{2-x}Sr_{x}NiO_{4} shows a large dielectric constant \epsilon ^{'} at high temperature and a step-like drop by a factor of 100 at a material-dependent low temperature T_{f}. T_{f} increases with frequency and the dielectric response shows universal scaling in a Cole-Cole plot, suggesting that a charge glass state is realized both in the cuprates and in the nickelates.