Mechanical control of crystal symmetry and superconductivity in Weyl semimetal MoTe 2

Semimetalic MoTe${}_{2}$ is an exciting material exhibiting both type-II Weyl nodes and superconductivity. Broken inversion symmetry is required for the Weyl semimetal phase, and this material is complicated by a structural phase transition between inversion symmetric (1T') and nonsymmetric phases (T${}_{d}$). Further, pressure suppresses the T${}_{d}$ phase and strongly enhances the superconducting transition temperature. The authors combined pressure-dependent neutron scattering, transport measurements, and first-principles calculations to deconvolve the structural phase transformation from the superconducting transition. Unexpectedly, both structural phases support superconductivity, and the authors show that anisotropic strain can be used to control which structure accommodates this pressure-enhanced superconductivity.