Gate-induced superconductivity in a monolayer topological insulator

• Published in: Science (American Association for the Advancement of Science) Vol. 362; no. 6417
• Main Authors: Sajadi, Ebrahim, Palomaki, Tauno, Fei, Zaiyao, Zhao, Wenjin, Bement, Philip, Olsen, Christian, Luescher, Silvia, Xu, Xiaodong, Folk, Joshua A., Cobden, David H.
• Format: Journal Article
• Language: English
• Published: United States AAAS 25.10.2018
• Subjects: Science & Technology - Other Topics
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aar4426

The layered semimetal tungsten ditelluride (WTe2) has recently been found to be a two-dimensional topological insulator (2D TI) when thinned down to a single monolayer, with conducting helical edge channels. We found that intrinsic superconductivity can be induced in this monolayer 2D TI by mild electrostatic doping at temperatures below 1 kelvin. The 2D TI–superconductor transition can be driven by applying a small gate voltage. This discovery offers possibilities for gate-controlled devices combining superconductivity and nontrivial topological properties, and could provide a basis for quantum information schemes based on topological protection.