Coupling type II Weyl semimetal MoTe₂ with a stronger s-wave superconductor: the competition with the inherent bulk superconducting condensate and the disloyal edge mode.

We report the effects of coupling the type II Weyl semimetal MoTe₂ with an s-wave superconductor that has a much larger superconducting gap. We fabricated nanodevices from exfoliated MoTe₂ crystals (60 – 120 nm in thickness) with Nb electrodes. Tuning the temperature T and the perpendicular magnetic field B, we explored two different regimes. In one, the injected s-wave and the MoTe₂ bulk condensates co-exist; in the other, only the injected condensate is present. Differential resistance (dV/dI) measurements revealed the competition of the two condensates. The transition from the superconducting state to the metallic state was stochastic, and the critical current I_c was greatly enhanced. In the absence of the MoTe2 bulk condensate, the injected condensate proximitized the edge mode of MoTe₂. The differential resistance versus magnetic field spectra exhibited oscillations of critical current, where the area associated with the frequency corresponded to the physical area of the sample.