  Due to the non-trivial topological band structure in type-II Weyl semimetal
Tungsten ditelluride (WTe2), unconventional properties may emerge in its
superconducting phase. While realizing intrinsic superconductivity has been
challenging in the type-II Weyl semimetal WTe2, proximity effect may open an
avenue for the realization of superconductivity. Here, we report the
observation of proximity-induced superconductivity with a long coherence length
along c axis in WTe2 thin flakes based on a WTe2/NbSe2 van der Waals
heterostructure. Interestingly, we also observe anomalous oscillations of the
differential resistance during the transition from superconducting to normal
state. Theoretical calculations show excellent agreement with experimental
results, revealing that such a sub-gap anomaly is the intrinsic property of
WTe2 in superconducting state induced by the proximity effect. Our findings
enrich the understanding of superconducting phase of type-II Weyl semimetals,
and pave the way for their future applications in topological quantum
computing.
