In topological semimetals, nodes appear at symmetry points in the Brillouin zone as a result of band inversion, and yield quasi-relativistic massless fermions at low energies. Cd3As2 is a three-dimensional topological semimetal that hosts two Dirac cones responsible for a variety of quantum phenomena. In this work, we demonstrate the strain tuning of the Dirac nodes of Cd3As2 through a combination of magnetooptical infrared spectroscopy and high-resolution X-ray diffraction studies performed on epitaxial films. In these thin films, we observe a giant enhancement of the node separation in momentum space by close to a factor of 4. A combination of experimental measurements and theoretical modelling allows relate the origin of this enhancement to a strengthening of the topological band inversion driven by lattice strain. Our results demonstrate how strain can be used as a knob to tune the topological properties of semimetals and to potentially enhance their performance and response for various applications.
@article{arxiv.2209.09779,
title = {Enhanced Dirac node separation in strained Cd3As2 topological semimetal},
author = {Gauthier Krizman and Joaquin Bermejo-Ortiz and Manik Goyal and Alexander C. Lygo and Jiashu Wang and Zhan Zhang and Badih A. Assaf and Susanne Stemmer and Louis-Anne de Vaulchier and Yves Guldner},
journal= {arXiv preprint arXiv:2209.09779},
year = {2022}
}