Temperature dependence of the optical spectral weight in the cuprates: Role of electron correlations

TL;DR

This study uses Dynamical Mean-Field Theory to analyze how strong electron correlations influence the temperature-dependent optical spectral weight in cuprates, revealing anomalies and multiple energy scales not explained by normal metal behavior.

Contribution

It demonstrates that strong electron correlations are responsible for the observed anomalies and multiple energy scales in the optical spectral weight of cuprates without fitting parameters.

Findings

Correlation effects explain anomalies in spectral weight.

Two distinct energy scales are identified.

Strong correlations are key to understanding cuprate behavior.

Abstract

We compare calculations based on the Dynamical Mean-Field Theory of the Hubbard model with the infrared spectral weight $W(\Omega,T)$ of La$_{2-x}$Sr$_x$CuO$_4$ and other cuprates. Without using fitting parameters we show that most of the anomalies found in $W(\Omega,T)$ with respect to normal metals, including the existence of two different energy scales for the doping- and the $T$-dependence of $W(\Omega,T)$, can be ascribed to strong correlation effects.