Gate-Accessible Superconductivity and Helical Modes in Monolayer WTe₂

I report on our transport measurements of electrostatically gated monolayer tungsten ditelluride (WTe₂), where we observe both superconductivity and helical edge modes in the same material. I will briefly introduce our experiments in the undoped regime which indicate that monolayer WTe₂ is a quantum spin Hall insulator with edge conduction dominating up to 100K. In the doped regime, the same material is a superconductor at record-low induced 2D carrier densities, with critical temperatures as high as 1 Kelvin. Unique among 2D electronic systems, monolayer WTe₂ is fully tunable from a gapped topological insulator state to an intrinsic superconducting state using only solid state electrostatic gates. New routes for topological quantum devices are now possible, in which electrostatically accessible superconductivity and helical modes can be naturally interfaced within the same crystal.