Pressure-induced superconductivity in trigonal layered PtBi 2 with triply degenerate point fermions

Materials with nonsaturating, extremely large magnetoresistance (XMR) attract continuous research interest due to their great potential in the fields of spintronics and magnetic sensors/switches. Here, we report the discovery of pressure-driven superconductivity (SC) in trigonal ${\mathrm{PtBi}}_{2}$, a semimetal material with nontrivial triply degenerate point fermions exhibiting a nonsaturating XMR effect, above a critical pressure of $\ensuremath{\sim}5--6$ GPa. The superconducting transition onset temperature is $\ensuremath{\sim}2$ K and displays a very weak pressure dependence across a broad pressure range of $\ensuremath{\sim}5--48$ GPa. The lattice structure of trigonal ${\mathrm{PtBi}}_{2}$ is stable against pressure at least to 12.9 GPa. Around the same critical pressure where the SC emerges, the Hall coefficient varies violently and shows a sign crossover from low pressure positive (hole dominated) to high pressure negative (electron dominated), probably indicating a close relationship between them.