  We report the synthesis of single-crystal NbC, a transition metal carbide
with various unusual properties. Transport, magnetic susceptibility, and
specific heat measurements demonstrate that NbC is a conventional
superconductor with a superconducting transition temperature ($T_c$) of 11.5 K.
Our theoretical calculations show that NbC is a type-II Dirac semimetal with
strong Fermi surface nesting, which is supported by our ARPES measurement
results. We also observed the superconducting gaps of NbC using angle-resolved
photoemission spectroscopy (ARPES) and found some unconventional behaviors.
These intriguing superconducting and topological properties, combined with the
high corrosion resistance, make NbC an ideal platform for both fundamental
research and device applications.
