In-situ uniaxial strain tuning of topological pentatellurides*

In recent years, the subject of topological order has been at the center of attention in condensed matter physics research. Topological materials, representing a new quantum state of matter, are a family of quantum materials with boundary states whose physical properties are robust against certain types of transformations or disorders. Therefore, there have been few examples for a topological phase transition realized experimentally, even fewer cases for an in-situ tuning of a topological phase. We have applied uniaxial strain along different crystallographic directions for a pentatelluride topological material and performed electrical transport measurements at low temperatures and high magnetic fields. We have observed a dramatic change of the resistivity, as a function of uniaxial strain, temperature, magnetic field and crystallographic direction. Our results point to a topological phase transition of the system tuned by uniaxial strain in situ.