Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan.
Phys Rev Lett. 2012 Nov 21;109(21):217004. doi: 10.1103/PhysRevLett.109.217004.
The existence of topological superconductors preserving time-reversal symmetry was recently predicted, and they are expected to provide a solid-state realization of itinerant massless Majorana fermions and a route to topological quantum computation. Their first likely example, Cu(x)Bi(2)Se(3), was discovered last year, but the search for new materials has so far been hindered by the lack of a guiding principle. Here, we report point-contact spectroscopy experiments suggesting that the low-carrier-density superconductor Sn(1-x)In(x)Te is accompanied by surface Andreev bound states which, with the help of theoretical analysis, would give evidence for odd-parity pairing and topological superconductivity. The present and previous finding of possible topological superconductivity in Sn(1-x)In(x)Te and Cu(x)Bi(2)Se(3) suggests that odd-parity pairing favored by strong spin-orbit coupling is likely to be a common underlying mechanism for materializing topological superconductivity.
最近有人预言了存在时间反演对称的拓扑超导体，它们有望在固体中实现无质量的迁移马约拉纳费米子，并为拓扑量子计算提供一种途径。去年发现了第一个可能的例子，即 Cu(x)Bi(2)Se(3)，但到目前为止，由于缺乏指导原则，新材料的寻找一直受到阻碍。在这里，我们报告了点接触光谱实验的结果，该实验表明低载流子密度超导体 Sn(1-x)In(x)Te 伴随着表面安德烈夫束缚态，通过理论分析，这将为奇宇称配对和拓扑超导提供证据。目前和之前在 Sn(1-x)In(x)Te 和 Cu(x)Bi(2)Se(3) 中发现的可能的拓扑超导性表明，由强自旋轨道耦合所支持的奇宇称配对很可能是实现拓扑超导性的共同潜在机制。
