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

Abstract

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