铁基超导涡旋演生马约拉纳零能模

作为马约拉纳零能模(MZM)的一种全新载体,具有拓扑能带结构的铁基超导块材--拓扑铁基超导体--近年来引起了学术界的广泛关注.由于同时具备单一材料、高温超导、强电子关联、拓扑能带等特质,拓扑铁基超导体成功规避了本征拓扑超导体和近邻异质结体系在实现MZM上的困难,为马约拉纳物理开辟了自赋性拓扑超导的新方向.时至今日,人们已经在多种拓扑铁基超导体的磁通涡旋中测量到了纯净的MZM.实验发现,铁基超导体系中演生的涡旋MZM信号明确、物理清晰,具有很好的应用前景.拓扑铁基超导体有望成长为研究马约拉纳物理和制备拓扑量子比特最重要的材料体系之一.本文以Fe(Te,Se)为主要对象详细介绍了铁基超导马约拉纳载体的思想起源和研究进展.在阐明Fe(Te,Se)拓扑能带结构和零能涡旋束缚态基本实验事实的基础上,本文将逻辑清晰地系统总结铁基超导涡旋演生MZM的主要实验观测和基本物理行为;借助波函数、准粒子中毒等实验,解析Fe(Te,Se)单晶中的涡旋MZM演生机制;结合现有马约拉纳理论,深入探讨铁基超导体中的马约拉纳对称性和准粒子拓扑本质的实验测量.最后,本文采用"从量子物理到量子工程"的视角,综合分析涡旋MZM在真实材料和实际实验中的鲁棒性,为未来潜在的工程应用提供有益指导.本文以物理原理为线,注重理论与实验结合,旨在搭建经典马约拉纳理论与新兴拓扑铁基超导体系之间的桥梁,帮助读者理解铁基超导涡旋中演生的MZM.

Emergent vortex Majorana zero mode in iron-based superconductors

During the recent years,the iron-based superconductors with a topological band structure have attracted intensive attention from the science community as a new and promising platform for emerging Majorana zero modes in their vortex core.These topological iron-based superconductors possess all of the desirable properties,i.e.single material,high-Tc superconductivity,strong electron-electron correlation and topological band structure,thus successfully avoiding the difficulties suffered by previous Majorana platforms,such as intrinsic topological superconductors and multiple types of proximitized heterostructures.So far,one has observed pristine vortex Majorana zero modes in several different compounds of iron-based superconductors.The systematic studies performed on those systems show that the vortex Majorana zero modes are quite evident experimentally and very clear theoretically,leading to a bright future in applications.The vortex cores of ironbased superconductors can become one of the major candidates for exploring topological quantum computing in the future.In this review article,we will focus on Fe(Te,Se)single crystal,to introduce the original ideas and research progress of the new emerging“iron home”for Majorana zero modes.Having elabrated the basic band structures and the experimental facts of the observed vortex zero modes in Fe(Te,Se),we will systematically summarize the main observations and fundamental physics of vortex Majorana zero modes in Fe(Te,Se).First of all,with the help of the observed behavior of Majorana wavefunction and quasiparticle poisioning,we will analyze the emerging mechanism of vortex Majorana zero modes in Fe(Te,Se).Then we will elaborate the measurements on Majorana symmetry and topological nature of vortex Majorana zero modes,assisted by several existing Majorana theories.After that,we will switch our view angle from quantum physics to quantum engineering,and comprehensively analyze the fate of vortex Majorana zero modes in a real material under a real environment,which may benefit the potential engineering applications in the future.This review article follows the physical properties of vortex Majorana zero modes,and emphasizes the link between theories and experiments.Our goal is to bridge the gap between the classical Majorana theories and the new emerging Majorana platform in iron-based superconductors,and help the readers to understand the experimental observations of the newly discovered“iron home”for Majoranas.