Dynamics of Correlated Two-Dimensional Materials: The2H−TaSe2Case

Abstract

We report a study of dc transport properties up to 600 K and of the optical response over a broad spectral range of the two-dimensional (2D) dichalcogenide $2H\ensuremath{-}{\mathrm{TaSe}}_{2}$. Our findings suggest a dynamics of the charge excitation spectrum dominated by two relevant features: a Drude contribution, which narrows with decreasing temperature, and a broad pseudogaplike feature in the midinfrared range, which is present at all temperatures below 300 K. The implications of these results with respect to the charge-density-wave phase transition at 122 K and more generally for the excitation spectrum of 2D correlated systems, e.g., the high temperature superconducting cuprates, will be addressed.