Pressure-induced superconductivity in topological heterostructure (PbSe)_5(Bi_2Se_3)_6

Recently, the natural heterostructure of (PbSe)_5-(Bi_2Se_3)_6 has been theoretically predicted and experimentally confirmed as a topological insulator. In this work, we induce superconductivity in (PbSe)_5(Bi_2Se_3)_6 by implementing high pressures. As the pressure increases up to 10 GPa, superconductivity with a critical temperature ( T _c) ~ 4.6 K suddenly appears, which is followed by an abrupt decrease. Remarkably, upon further compression above 30 GPa, a new superconducting state arises, where pressure raises the T _c to an unsaturated 6.0 K within the limit of our research. Combining X-ray diffraction and Raman spectroscopy, we suggest that the emergence of the two distinct superconducting states occurs concurrently with the pressure-induced structural transition in this topological heterostructure (PbSe)_5(Bi_2Se_3)_6. 最近, 天然异质结(PbSe)_5(Bi_2Se_3)_6在理论上预测并实验证实为拓扑绝缘体. 本文通过高压原位量子调控在(PbSe)_5(Bi_2Se_3)_6中成功引入超导电性. 当压力增加到10 GPa时, 超导电性突然出现, Tc约为4.6 K, 随后 T _c急剧下降. 值得注意的是, 当进一步施加压力到30 GPa以上时, 出现了一种新的超导态, 且 T _c直到本实验最高压力仍未饱和. 结合XRD和拉曼光谱, 我们认为(PbSe)_5(Bi_2Se_3)_6中两个超导态的出现与压力诱导的结构相变有关. 拓扑异质结压力下出现新的量子态, 为进一步研究拓扑和超导的关系提供了一个良好的平台.