Giant enhancement of superconductivity in few layers MoTe₂*

Abstract

Recently, the layered transition metal dichalcogenide 1T′ MoTe 2 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 MoTe 2 prepared by mechanical exfoliation. We find that MoTe 2 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 c 2|| ) is much higher than the Pauli paramagnetic limit, implying that the MoTe 2 flakes have Zeeman-protected Ising superconductivity. Furthermore, the T c and H c 2 can be tuned by up to 320 mK and 400 mT by applying a gate voltage. Our result indicates that MoTe 2 flake is a good candidate for studying exotic superconductivity with nontrivial topological properties.