Gate Tunable Superconductivity in monolayer <i>β</i>-MoTe₂

Due to the emergence of mechanically exfoliated, highly crystalline superconductors, research into superconducting-insulator transitions and quantum phase transitions in the low disorder limit has become more accessible. This allows for the exploration of novel layered superconductors in the few layer limit. Materials such as bilayer NbSe2 exhibit a Bose-metal state, while others like WTe2 can have 3 distinct phases, modified by the application of a gate voltage.
Here we report the observation of a superconducting transition in a single atomic layer of β-MoTe₂ fully encapsulated in h-BN, and contacted via palladium, with a 285 nm silicon oxide back-gate. Monolayers of β-MoTe₂ grown by chemical vapor deposition and contacted via traditional e-beam lithography methods have shown sheet resistances on the order of several kΩ. However, with encapsulation and contacts fabricated without exposure to air we are able to obtain a sheet resistance down to 170 Ω, around twice the normal state resistance for what has been found in graphene contacted, h-BN encapsulated bilayer NbSe₂.