Abstract
We present the first experimental evidence of a topological phase transition in a monoelemental quantum spin Hall insulator. Particularly, we show that low-buckled epitaxial germanene is a quantum spin Hall insulator with a large bulk gap and robust metallic edges. Applying a critical perpendicular electric field closes the topological gap and makes germanene a Dirac semimetal. Increasing the electric field further results in the opening of a trivial gap and disappearance of the metallic edge states. This electric field-induced switching of the topological state and the sizable gap make germanene suitable for room-temperature topological field-effect transistors, which could revolutionize low-energy electronics.
- Received 9 November 2022
- Accepted 24 March 2023
DOI:https://doi.org/10.1103/PhysRevLett.130.196401
© 2023 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Quantum Spin Hall Effect Seen in Graphene Analog
Published 12 May 2023
Germanene undergoes a topological phase transition and then becomes a normal insulator when the strength of an applied electric field is dialed up.
See more in Physics