By means of pump-probe time- and angle-resolved photoelectron spectroscopy, we provide evidence of a sizeable reduction of the Fermi velocity of out-of-equilibrium Dirac bands in the quasi-two-dimensional semimetal BaNiS2. First-principle calculations indicate that this band renormalization is ascribed to a change in non-local electron correlations driven by a photo-induced enhancement of screening properties. This effect is accompanied by a slowing down of the Dirac fermions and by a non-rigid shift of the bands at the center of the Brillouin zone. This result suggests that other similar electronic structure renormalizations may be photoinduced in other materials in presence of strong non-local correlations.
@article{arxiv.1912.13254,
title = {Photoinduced renormalization of Dirac states in BaNiS$_2$},
author = {Niloufar Nilforoushan and Michele Casula and Marco Caputo and Evangelos Papalazarou and Jonathan Caillaux and Zhesheng Cheng and Luca Perfetti and Adriano Amaricci and David Santos-Cottin and Yannick Klein and Andrea Gauzzi and Marino Marsi},
journal= {arXiv preprint arXiv:1912.13254},
year = {2021}
}