Layered transition metal chalcogenides are promising hosts of electronic Weyl nodes and topological superconductivity. MoTe₂ is a striking example that harbors both non-centrosymmetric T_d and centrosymmetric T' phases. In this talk we present neutron scattering and transport mreasuremens along with Density functional theory (DFT) calculations to suggest a path towards the realization and control of these topological states of the type-II Weyl semimetal and superconductor MoTe₂ through the application of pressure [1]. DFT calculations reveal that the strength of the electron-phonon coupling is similar for both crystal structures. Finally, we show that there is a critical pressure characterized by unique coherent quantum oscillations, indicating that the change in topology between two phases give rise to a new topological interface state[2]. We present periodic and finite slab calculations of this new interface state which is in excellent agreement with the observed quantum oscillation frequencies.

[1] C. Heies et al, “Mechanical control of crystal symmetry and superconductivity in Weyl semimetal MoTe2”, Phys. Rev. Materials 2, 074202 (2018)
[2] I-Lin Liu et al, Quantum oscillations from networked topological interfaces in a Weyl
Semimetal, arxiv.org/1905.02277 (2019).