Effect of electronic correlations on the metal-insulator transition of $\alpha$-(BEDT-TTF)${}_2$I${}_3$: theoretical and experimental investigations of its optical properties

Abstract

The organic salt $\alpha$-(BEDT-TTF)${}_2$I${}_3$ is considered a model system for metal-insulator transition due to electronic charge ordering at $T_{\mathrm{CO}}=135$~K. The optical properties obtained from polarized reflection measurements above and below $T_{\mathrm{CO}}$ can be well described by calculations based on first-principle density-functional theory (DFT). We discuss the effect of electronic correlations on the metal-insulator transition.

6 pages, 4 figures