在超导的拓扑晶体绝缘体Sn1-xPbxTe中探测多重Majorana零能模

Majorana零能模(MZM)作为拓扑超导体中一种新奇的准粒子，因拓扑量子计算的潜在应用成为当前的研究热点。人们已在超导体与拓扑绝缘体形成的异质结中探测到了MZM。最新理论表明超导的拓扑晶体绝缘体中也存在MZM，而且多个MZMs可以共存于一个磁通中心，然而实验上还未探测到该现象。我们前期研究发现调控衬底的温度可制备出高质量的Sn1-xPbxTe-Pb侧向和纵向两种异质结，它们之中都存在很强的超导近邻效应，利用超导针尖从态密度上可直接分辨出其中的拓扑超导电性。因此我们认为如果能够制备出台面较大的Sn1-xPbxTe薄膜，将更有利于探测量子磁通。本项目拟在超导的拓扑晶体绝缘体Sn1-xPbxTe中探测多重的MZMs，并对其特殊性质展开研究，比如MZM实空间中的分布，自旋特性以及量子化电导行为等。该研究不仅有助于理解新型拓扑超导体材料的产生机制，对未来实现拓扑量子计算也起到极大地推动作用。

As a novel quasiparticle in topological superconductors, the Majorana zero mode (MZM) has become a hot topic in current research due to the potential application of topological quantum computation. The MZM has been detected in the heterostructure formed by superconductor and topological insulator. The latest theory suggests that there also exist MZMs in the vortices in the superconducting topological crystalline insulator, for which it's very special that multiple MZMs can coexist in a single vortex. However, this phenomenon has not been detected experimentally. Our previous study found that two high quality Sn1-xPbxTe-Pb lateral and vertical heterostructures can be prepared by adjusting the substrate temperature. There is a strong superconducting proximity effect in both of them, and the topological superconductivity can be directly distinguished from the density of states by using a superconducting tip. Therefore, we believe that if Sn1-xPbxTe thin films with large terraces can be prepared, it will be more beneficial to detect the quantum magnetic vortex. In this project, we intend to detect multiple MZMs in the superconducting topological crystalline insulator Sn1-xPbxTe, and study their special properties, such as distribution of MZMs in real space, spin properties and quantized conductance behavior. This project research not only helps us understand the mechanism of new topological superconductors, but also greatly promotes the realization of topological quantum computing in the future.