铁基超导体中的马约拉纳零能模及其阵列构筑

Majorana zero mode and its lattice construction in iron-based superconductors

马约拉纳零能模服从非阿贝尔统计,其编织操作可用于构筑拓扑量子比特,是拓扑量子计算的基本单元,可从原理上解决量子计算中环境噪声带来的退相干问题.现有的马约拉纳零能模平台包括复合异质结构,如拓扑绝缘体/超导体、半导体纳米线/超导体或一维磁性原子链/超导体等,以及单一材料,如2M-WS_(2),4Hb-TaS_(2)和铁基超导体等.铁基超导体中的马约拉纳零能模具有材料平台简单、零能模纯净以及存活温度较高等一系列优势,引起了广泛关注.最近,大面积、有序和可调控的马约拉纳零能模晶格阵列在铁基超导体LiFeAs中被观测到,为未来的拓扑量子计算提供了一个理想平台.本综述首先回顾铁基超导体中马约拉纳零能模的实验观测,其中将重点介绍FeTe_(0.55)Se_(0.45),(Li_(0.84)Fe_(0.16))OHFeSe,CaKFe_(4)As_(4)和LiFeAs等材料体系.接着介绍给出铁基超导体中马约拉纳零能模关键性实验证据的一系列工作.然后进一步详细介绍近期LiFeAs中观测到有序和可调马约拉纳零能模晶格阵列的工作.最后给出总结和对未来马约拉纳领域研究的展望.

Majorana zero modes(MZMs)obey non-Abelian braiding statistics.The braiding of MZMs can be used to construct the basic unit−topological qubit−of the topological quantum computation,which is immune to environmental noise and can achieve fault-tolerant quantum computation.The existing MZM platforms include hybrid structures such as topological insulator/superconductor,semiconducting nanowire/superconductor and 1d magnetic atomic chain/superconductor,and single materials such as 2M-WS_(2),4Hb-TaS_(2),and iron-based superconductors(IBSs).The IBSs have advantages such as easy to fabricate,pure MZMs and high surviving temperatures of MZMs.Recently,a large-scale,ordered and tunable MZM lattice has been observed in LiFeAs,which provides a promising platform to future topological quantum computation.In this paper,first,we review the experimental observations of MZMs in IBSs,focusing on FeTe_(0.55)Se_(0.45),(Li_(0.84)Fe_(0.16))OHFeSe,CaKFe_(4)As_(4)and LiFeAs.Next,we introduce the critical experimental evidences of the MZMs.We also review the recent research work on the ordered and tunable MZM lattice in LiFeAs.Finally,we give conclusion and perspective on future Majorana research.