A phase transition between topologically distinct insulating phases involves closing and reopening of the bandgap. Close to this topological phase transition, the bulk energy spectrum is characterized by a massive Dirac dispersion, where the mass plays the role of bandgap. Here we report the observation of a non-monotonic strain dependence of resistivity and negative longitudinal magnetoresistance in ZrTe5, which is known to host massive Dirac Fermions in the bulk. This non-monotonic strain dependence is consistent with the closing and reopening of the bandgap at the Brillouin-zone center, indicative of a topological phase transition. This observation suggests that the topological state of ZrTe5 is highly sensitive to uniaxial stress. Our study presents a promising platform for continuous in-situ control of nontrivial topological properties of materials.
@article{arxiv.1808.07898,
title = {Evidence for a strain tuned topological phase transition in ZrTe5},
author = {Joshua Mutch and Wei-Chih Chen and Preston Went and Tiema Qian and Ilham Zaky Wilson and Anton Andreev and Cheng-Chien Chen and Jiun-Haw Chu},
journal= {arXiv preprint arXiv:1808.07898},
year = {2019}
}