  We report the experimental observation of Ising superconductivity in
3-dimensional NbSe2 stacked with single-layer MoS2. The angular dependence of
the upper critical magnetic field and the temperature dependence of the upper
parallel critical field confirm the appearance of two-dimensional Ising
superconductivity in the 3-dimensional NbSe2 with single-layer MoS2 overlay. We
show that the superconducting phase has strong Ising spin-orbit correlations
which make the holes spin non-degenerate. Our observation of Ising
superconductivity in heterostructures of few-layer NbSe2 of thickness ~ 15 nm
with single-layer MoS2 raises the interesting prospect of observing topological
chiral superconductors with nontrivial Chern numbers in a momentum-space
spin-split fermionic system.
