Electrically tunable low-density superconductivity in a monolayer topological insulator

• Main Authors: Fatemi, Valla (Author), Wu, Sanfeng (Author), Cao, Yuan (Author), Bretheau, Landry (Author), Gibson, Quinn D. (Author), Watanabe, Kenji (Author), Taniguchi, Takashi (Author), Cava, Robert J. (Author), Jarillo-Herrero, Pablo (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Association for the Advancement of Science (AAAS), 2020-06-02T18:35:50Z.
• Subjects: Article
• Online Access: Get fulltext

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.
AFOSR Grant No. FA9550-16-1-0382
Gordon and Betty Moore Foundation's EPiQS Initiative through Grant No. GBMF4541
DOE, Basic Energy Sciences Office, under Award No. DE-SC0001088