Pressure-induced topological phase transition in 2D Tellurium*

Topologically non-trivial electronic band structures in quantum materials have attracted worldwide interest due to their intriguing physical properties and potential applications. A topological phase transition from the topologically trivial phase to the topologically non-trivial phase offers a promising method to control and study the physical properties of topological materials. Here, we report the electrical transport evidence of topological phase transition from a semiconductor to a Weyl semimetal in two-dimensional Tellurium (2D Te) under pressure (up to 2.47 GPa). The highly tunable chemical potential controlled by the back gate voltage in 2D Te provides a comprehensive understanding of the topological band structure. The pressure-induced insulator-to-metal transition, two-carrier transport, and the non-trivial π phase shift in quantum oscillations are observed in the 2D Te Weyl semimetal phase. Using 2D Te as an example, our work opens the door for the controllable electronic transport study on topological phase transitions.