Using time- and angle-resolved photoemission spectroscopy, we study the response of metallic single layer TaS2 in the 1H structural modification to the generation of excited carriers by a femtosecond laser pulse. A complex interplay of band structure modifications and electronic temperature increase is observed and analyzed by direct fits of model spectral functions to the two-dimensional (energy and k-dependent) photoemission data. Upon excitation, the partially occupied valence band is found to shift to higher binding energies by up to 150 meV, accompanied by electronic temperatures exceeding 3000~K. These observations are explained by a combination of temperature-induced shifts of the chemical potential, as well as temperature-induced changes in static screening. Both contributions are evaluated in a semi-empirical tight-binding model. The shift resulting from a change in the chemical potential is found to be dominant.
@article{arxiv.1901.07819,
title = {Transient Hot Electron Dynamics in Single-Layer TaS$_2$},
author = {Federico Andreatta and Habib Rostami and Antonija Grubišić Čabo and Marco Bianchi and Charlotte E. Sanders and Deepnarayan Biswas and Cephise Cacho and Alfred J. H. Jones and Richard T. Chapman and Emma Springate and Phil D. C. King and Jill A. Miwa and Alexander Balatsky and Søren Ulstrup and Philip Hofmann},
journal= {arXiv preprint arXiv:1901.07819},
year = {2019}
}