Pressure-induced topological phase transition in noncentrosymmetric elemental Tellurium

TL;DR

This study demonstrates a pressure-induced topological phase transition in elemental tellurium, transforming it from a semiconductor to a Weyl semimetal, evidenced by transport measurements and quantum oscillation analysis.

Contribution

It provides experimental evidence of a pressure-driven topological phase transition in elemental tellurium, highlighting the role of external pressure in tuning electronic band topology.

Findings

Observation of anomaly in quantum oscillations at critical pressure

Reduction of effective cyclotron mass near transition

Band crossing and deformation under pressure

Abstract

Recent progress in understanding the electronic band topology and emergent topological properties encourage us to reconsider the band structure of well-known materials including elemental substances. Controlling such a band topology by external field is of particular interest from both fundamental and technological view point. Here we report the pressure-induced topological phase transition from a semiconductor to a Weyl semimetal in elemental tellurium probed by transport measurements. Pressure variation of the periods of Shubnikov-de Haas oscillations, as well as oscillations phases, shows an anomaly around the pressure theoretically predicted for topological phase transition. This behavior can be well understood by the pressure-induced band deformation and resultant band crossing effect. Moreover, effective cyclotron mass is reduced toward the critical pressure, potentially reflecting the emergence of massless linear dispersion. The present result paves the way for studying the electronic band topology in well-known compounds and topological phase transition by the external field.