Effect of pressure on structural and electronic properties of the noncentrosymmetric superconductor Rh2Mo3N

Noncentrosymmetric molybdenum nitride Rh2Mo3N is a conventional s-wave superconductor at ambient pressure. Here we report the evolution of structural and electronic properties of Rh2Mo3N under high pressure. X-ray diffraction measurements reveal the stability of pristine beta-Mn-type cubic structure up to 47.9 GPa, accompanied by the continuously enhanced distortion of Mo6N octahedra. Electronic transport experiments show the robustness of superconductivity under pressure, i.e., the superconducting transition temperature T-c varies only similar to 0.7 K upon compression up to 38.5 GPa. Meanwhile, detailed analyses of both structural and transport results consistently reveal a critical pressure of similar to 14.0 GPa. In agreement with the enhancement of octahedral distortion, the temperature dependence of upper critical magnetic field accords with a p-wave model at 22.0 GPa and an s-wave model at 6.0 GPa. These results suggest the emergence of novel superconductivity in the distorted Rh2Mo3N cubic phase under pressure, which could be attributed to the enhanced strength of antisymmetric spin-orbit coupling (ASOC) via pressure-modified local octahedral distortion. Our findings may shed light on the searching and understanding of unique triplet-pairing superconductivity in other inversion-broken superconductors with strong ASOC.