Giant enhancement of superconductivity in few layers MoTe2*

Abstract

Recently, the layered transition metal dichalcogenide 1T′ MoTe2 has attracted considerable attention due to its non-saturating magnetoresistance, type-II Weyl semimetal properties, superconductivity, and potential candidate for two-dimensional (2D) topological insulator in the single- and few-layer limit. Here in this work, we perform systematic transport measurements on thin flakes of MoTe2 prepared by mechanical exfoliation. We find that MoTe2 flakes are superconducting and have an onset superconducting transition temperature T c up to 5.3 K, which significantly exceeds that of its bulk counterpart. The in-plane upper critical field (H c2||) is much higher than the Pauli paramagnetic limit, implying that the MoTe2 flakes have Zeeman-protected Ising superconductivity. Furthermore, the T c and H c2 can be tuned by up to 320 mK and 400 mT by applying a gate voltage. Our result indicates that MoTe2 flake is a good candidate for studying exotic superconductivity with nontrivial topological properties.