Topological Dirac line nodes and superconductivity coexist in SnSe at high pressure

Article

关键词: PHASE-TRANSITION;    TEMPERATURE;    DIFFRACTION;    SCHEMES;    BI2SE3;    ORDER;    POWER;   

DOI  :  10.1103/PhysRevB.96.165123

来源: SCIE

【 摘 要 】

We report on the discovery of a pressure-induced topological and superconducting phase of SnSe, a material which attracts much attention recently due to its superior thermoelectric properties. In situ high-pressure electrical transport and synchrotron x-ray diffraction measurements show that the superconductivity emerges along with the formation of a CsCl-type structural phase of SnSe above around 27 GPa, with amaximum critical temperature of 3.2 K at 39 GPa. Based on ab initio calculations, this CsCl-type SnSe is predicted to be a Dirac line-node (DLN) semimetal in the absence of spin-orbit coupling, whose DLN states are protected by the coexistence of time-reversal and inversion symmetries. These results make CsCl-type SnSe an interesting model platform with simple crystal symmetry to study the interplay of topological physics and superconductivity.

【 授权许可】

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