  In recent years, layered transition-metal dichalcogenides (TMDs) have
attracted considerable attention because of their rich physics; for example,
these materials exhibit superconductivity, charge density waves, and the valley
Hall effect. As a result, TMDs have promising potential applications in
electronics, catalysis, and spintronics. Despite the fact that the majority of
related research focuses on semiconducting TMDs (e.g., MoS2), the
characteristics of WTe2 are provoking strong interest in semimetallic TMDs with
extremely large magnetoresistance, pressure-driven superconductivity, and the
predicted Weyl semimetal (WSM) state. In this work, we investigate the sister
compound of WTe2, MoTe2, which is also predicted to be a WSM and a quantum spin
Hall insulator in bulk and monolayer form, respectively. We find that MoTe2
exhibits superconductivity with a resistive transition temperature Tc of 0.1 K.
The application of a small pressure (such as 0.4 GPa) is shown to dramatically
enhance the Tc, with a maximum value of 8.2 K being obtained at 11.7 GPa (a
more than 80-fold increase in Tc). This yields a dome-shaped superconducting
phase diagram. Further explorations into the nature of the superconductivity in
this system may provide insights into the interplay between strong correlations
and topological physics.
