高质量窄禁带半导体/超导体异质纳米结构的原位分子束外延制备及拓扑量子比特构筑

本申请瞄准项目申请指南中“能够展示马约拉纳零能模或其它非阿贝尔任意子的各种高质量异质结等材料的制备及基于各类量子态的量子比特构筑”的研究方向，拟采用分子束外延方法，围绕窄禁带半导体InAs和InSb材料体系，在III-V族半导体及Si等衬底上研究高质量窄禁带半导体纳米线的平面选区外延，开展具有高临界磁场和高临界温度的超导金属在这些平面窄禁带半导体纳米线侧壁的低温原位外延。在此基础上，发展高质量窄禁带半导体/超导体异质结纳米线网络的平面选区外延技术。最终制备出界面达原子级平整、具有硬超导能隙，并能够展示马约拉纳零能模的高质量窄禁带半导体/超导体异质结材料。基于这些高质量材料开展两个马约拉纳态之间的电子“隐形传态”等实验，制备出一个拓扑量子比特器件并探索其输运性质。通过项目的开展，为最终实现拓扑量子计算机等量子技术提供关键材料并奠定物理基础。

The research directions we followed in the application guidelines are “Preparation of high-quality heterostructures which can exhibit Majorana zero modes or other non-Abelian anyons and construction of quantum qubits based on various quantum states”. This project focuses on InAs and InSb and aims at in situ molecular-beam epitaxy growth of narrow bandgap semiconductor-superconductor hetero-nanostructures for the realization of topological Majorana qubits. We first plan to realize the selective-area growth of high-quality in planar narrow bandgap semiconductor nanowires on the III-V semiconductors, Si and other substrates by MBE. After that, we plan to in situ grow superconductor metals with a high critical magnetic field and a high transition temperature on these high-quality in planar narrow bandgap semiconductor nanowires. On this basis, we also plan to develop the growth technique on the selective-area MBE growth of high-quality in planar narrow bandgap semiconductor-superconductor networks. Based on the optimization of material quality and the transport properties, we attempt to grow the narrow bandgap semiconductor-superconductor hetero-nanostructures with the interfaces of atomic scale uniformity and hard superconducting gaps, and these high-quality hetero-nanostructures can be used to exhibit Majorana zero modes. Besides, the experiments such as electron teleportation between two Majorana states will be carried out on these high-quality hetero-nanostructures. It is expected that a topological qubit device will be realized and its transport properties will be well studied. We hope that this project can provide key materials and physical basis for realizing the topological quantum computer and other quantum information technologies.