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In a topological insulator the metallic surface states are easily
distinguished from the insulating bulk states (FuKane07). By contrast, in a
topological superconductor (FuKane08,Qi,FuBerg,Oppen), much less is known about
the relationship between an edge supercurrent and the bulk pair condensate. Can
we force their pairing symmetries to be incompatible? In the superconducting
state of the Weyl semimetal MoTe$_2$, an edge supercurrent is observed as
oscillations in the current-voltage (\emph{I-V}) curves induced by fluxoid
quantization (Wang). We have found that the $s$-wave pairing potential of
supercurrent injected from niobium contacts is incompatible with the intrinsic
pair condensate in MoTe$_2$. The incompatibility leads to strong stochasticity
in the switching current $I_c$ as well as other anomalous properties such as an
unusual antihysteretic behavior of the ``wrong'' sign. Under supercurrent
injection, the fluxoid-induced edge oscillations survive to much higher
magnetic fields \emph{H}. Interestingly, the oscillations are either very noisy
or noise-free depending on the pair potential that ends up dictating the edge
pairing. Using the phase noise as a sensitive probe that eavesdrops on the
competiting bulk states, we uncover an underlying blockade mechanism whereby
the intrinsic condensate can pre-emptively block proximitization by the Nb pair
potential depending on the history.
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