Ambipolar Superconductivity with Strong Pairing Interaction in Monolayer 1T′-MoTe₂

Abstract

Gate tunable two-dimensional (2D) superconductors offer significant advantages in studying superconducting phase transitions. Here, we address superconductivity in exfoliated 1T′-MoTe2 monolayers with an intrinsic band gap of ∼7.3 meV using field effect doping. Despite large differences in the dispersion of the conduction and valence bands, superconductivity can be achieved easily for both electrons and holes. The onset of superconductivity occurs near 7–8 K for both charge carrier types. This temperature is much higher than that in bulk samples. Also the in-plane upper critical field is strongly enhanced and exceeds the BCS Pauli limit in both cases. Gap information is extracted using point-contact spectroscopy. The gap ratio exceeds multiple times the value expected for BCS weak-coupling. All of these observations suggest a strong enhancement of the pairing interaction.

Promoted Electronic Coupling of Acoustic Phonon Modes in Doped Semimetallic MoTe2

“…During the preparation of the response of the manuscript, there are two additional experimental demonstrations of superconductivity in bilayer T d -MoTe 2 (ref ) and monolayer 1T′-MoTe 2 (ref ) controlled by doping.…”