Electrically tunable low-density superconductivity in a monolayer topological insulator

Turning on superconductivity in a topologically nontrivial insulator may provide a route to search for non-Abelian topological states. However, existing demonstrations of superconductor-insulator switches have involved only topologically trivial systems. Here we report reversible, in situ electrostatic on-off switching of superconductivity in the recently established quantum spin Hall insulator monolayer tungsten ditelluride (WTe2). Fabricated into a van der Waals field-effect transistor, the monolayer’s ground state can be continuously gate-tuned from the topological insulating to the superconducting state, with critical temperatures Tc up to ~1 kelvin. Our results establish monolayer WTe2 as a material platform for engineering nanodevices that combine superconducting and topological phases of matter.

Source: ScienceNOW - November 22, 2018 Category: Science Authors: Fatemi, V., Wu, S., Cao, Y., Bretheau, L., Gibson, Q. D., Watanabe, K., Taniguchi, T., Cava, R. J., Jarillo-Herrero, P. Tags: Materials Science, Physics reports Source Type: news