Similar ultrafast dynamics of several dissimilar Dirac and Weyl semimetals
Abstract
Recent years have seen the rapid discovery of solids whose low-energy electrons have a massless, linear dispersion, such as Weyl, line-node, and Dirac semimetals. The remarkable optical properties predicted in these materials show their versatile potential for optoelectronic uses. However, little is known of their response in the picoseconds after absorbing a photon. Here we measure the ultrafast dynamics of four materials that share non-trivial band structure topology but that differ chemically, structurally, and in their low-energy band structures: ZrSiS, which hosts a Dirac line node and Dirac points; TaAs and NbP, which are Weyl semimetals; and SrMnSb, in which Dirac fermions coexist with broken time-reversal symmetry. After photoexcitation by a short pulse, all four relax in two stages, first sub-picosecond, and then few-picosecond. Their rapid relaxation suggests that these and related materials may be suited for optical switches and fast infrared detectors. The complex change of refractive index shows that photoexcited carrier populations persist for a few picoseconds.
Keywords
Cite
@article{arxiv.1712.06754,
title = {Similar ultrafast dynamics of several dissimilar Dirac and Weyl semimetals},
author = {Chris P. Weber and Bryan S. Berggren and Madison G. Masten and Thomas C. Ogloza and Skylar Deckoff-Jones and Julien Madéo and Michael K. L. Man and Keshav M. Dani and Lingxiao Zhao and Genfu Chen and Jinyu Liu and Zhiqiang Mao and Leslie M. Schoop and Bettina Lotsch and Stuart S. P. Parkin and Mazhar Ali},
journal= {arXiv preprint arXiv:1712.06754},
year = {2017}
}