Pressure-induced superconductivity in trigonal layered <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>PtBi</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> with triply degenerate point fermions
Jing Wang, Xuliang Chen, Yonghui Zhou, Chao An, Ying Zhou, Chuanchuan Gu, Mingliang Tian, Zhaorong Yang
Abstract
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.