  Here we report the observation of pressure-induced superconductivity in
type-II Weyl semimetal (WSM) candidate NbIrTe4 and the evolution of its Hall
coefficient (RH), magnetoresistance (MR), and lattice with increasing pressure
to ~57 GPa. These results provide a significant opportunity to investigate the
universal high-pressure behavior of ternary WSMs, including the sister compound
TaIrTe4 that has been known through our previous studies. We find that the
pressure-tuned evolution from the WSM to the superconducting (SC) state in
these two compounds exhibit the same trend, i.e., a pressure-induced SC state
emerges from the matrix of the non-superconducting WSM state at ~ 27 GPa, and
then the WSM state and the SC state coexist up to 40 GPa. Above this pressure,
an identical high-pressure behavior, characterized by almost the same value of
RH and MR in its normal state and the same value of Tc in its SC state, appears
in both compounds. Our results not only reveal a universal connection between
the WSM state and SC state, but also demonstrate that NbIrTe4 and TaIrTe4 can
make the same contribution to the normal and SC states that inhabit in the
high-pressure phase, although these two compounds have dramatically different
topological band structure at ambient pressure.
