Lattice-distortion-enhanced electron-phonon coupling and Fermi surface nesting in 1T-TaS2

The temperature dependence of the electronic structure of the quasi-two-dimensional material 1T-TaS2 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 latticedistortion enhanced electron-phonon interaction.