Evidence for a strain tuned topological phase transition in ZrTe5

TL;DR

This study demonstrates that applying uniaxial strain to ZrTe5 induces a topological phase transition, evidenced by non-monotonic resistivity and magnetoresistance changes, highlighting strain as a tool to control topological states.

Contribution

It provides experimental evidence of a strain-tuned topological phase transition in ZrTe5 through transport measurements.

Findings

Non-monotonic strain dependence of resistivity observed.

Negative longitudinal magnetoresistance detected.

Bandgap closing and reopening at the Brillouin-zone center inferred.

Abstract

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.