Lattice-distortion-enhanced electron-phonon coupling and Fermi surface nesting in1T−TaS2

Abstract

The temperature dependence of the electronic structure of the quasi-two-dimensional material $1T\text{−}\mathrm{Ta}{\mathrm{S}}_2$ is revisited by considering angle-resolved photoemission spectroscopy (ARPES) and density functional theory to calculate the imaginary part of the static electronic susceptibility characterizing the nesting strength. While nesting appears to play a role in the high temperature phase, the ARPES line shapes reveal peculiar spectral properties which are not consistent with the standard two-dimensional Peierls scenario for the formation of a charge density wave. The temperature dependence of these anomalous spectral features suggests a lattice-distortion enhanced electron-phonon interaction.