Electronic structure of encapsulated mono- and bilayer T_d -MoTe₂

Bulk orthorhombic T_d -MoTe₂ is a type-II Weyl semimetal with topological Fermi arc surface states and becomes superconducting at a critical temperature of T_c = 0.1 K. Remarkably, superconductivity becomes far more robust in the 2D limit, contrary to generic models and the established trend in ultrathin metal films. Recent transport measurements reported a gradual increase in T_c as the thickness is reduced with T_c reaching 7.6 K in the monolayer. The reasons for the strong increase in T_c as well as the nature of the superconducting state remain unknown. Here, we present the electronic structure of exfoliated mono- and bilayer T_d -MoTe₂ probed by micro-focused angle-resolved photoemission. Our thickness-dependent measurements reveal that mono- and bilayer MoTe₂ are both compensated metals. The electron pocket of monolayer MoTe₂ shows signatures of strong coupling to optical phonons with a coupling strength of λ ≈ 1.5. In bilayer MoTe₂ electron-phonon coupling is weaker and differs less between electron and hole pocket.