Kong P P, Sun F, Xing L Y, Zhu J, Zhang S J, Li W M, Liu Q Q, Wang X C, Feng S M, Yu X H, Zhu J L, Yu R C, Yang W G, Shen G Y, Zhao Y S, Ahuja R, Mao H K, Jin C Q
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
1] Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2] Center for High Pressure Science &Technology Advanced Research (HPSTAR), Shanghai, China.
Sci Rep. 2014 Oct 20;4:6679. doi: 10.1038/srep06679.
Recently, A2B3 type strong spin orbital coupling compounds such as Bi2Te3, Bi2Se3 and Sb2Te3 were theoretically predicated to be topological insulators and demonstrated through experimental efforts. The counterpart compound Sb2Se3 on the other hand was found to be topological trivial, but further theoretical studies indicated that the pressure might induce Sb2Se3 into a topological nontrivial state. Here, we report on the discovery of superconductivity in Sb2Se3 single crystal induced via pressure. Our experiments indicated that Sb2Se3 became superconductive at high pressures above 10 GPa proceeded by a pressure induced insulator to metal like transition at ~3 GPa which should be related to the topological quantum transition. The superconducting transition temperature (TC) increased to around 8.0 K with pressure up to 40 GPa while it keeps ambient structure. High pressure Raman revealed that new modes appeared around 10 GPa and 20 GPa, respectively, which correspond to occurrence of superconductivity and to the change of TC slop as the function of high pressure in conjunction with the evolutions of structural parameters at high pressures.
最近，理论预测诸如Bi2Te3、Bi2Se3和Sb2Te3等A2B3型强自旋轨道耦合化合物为拓扑绝缘体，并通过实验得到了证实。另一方面，其对应化合物Sb2Se3被发现是拓扑平凡的，但进一步的理论研究表明，压力可能会使Sb2Se3进入拓扑非平凡状态。在此，我们报告了通过压力诱导在Sb2Se3单晶中发现超导性。我们的实验表明，Sb2Se3在高于10 GPa的高压下变成超导，在约3 GPa时先经历压力诱导的绝缘体到金属样转变，这应该与拓扑量子转变有关。超导转变温度（TC）随着压力增加到40 GPa而升高到约8.0 K，同时保持其常压结构。高压拉曼光谱显示，分别在10 GPa和20 GPa左右出现了新模式，这与超导性的出现以及TC随高压变化的斜率变化有关，同时也与高压下结构参数的演变有关。
