EAGER: BRAIDING: Braiding Majorana bound states in two-dimensional epitaxial semiconductor-superconductor structures

摘要：当半导体靠近超导材料时，其物理性质会发生变化。以一种可控的方式将半导体与超导体连接在一起，可以控制这些新特性。当界面上的条件合适时，新的行为类型可能会出现。例如，称为马约拉纳零模式的紧急状态可以在这个界面上形成，并表现为称为零偏置峰的特定测量特征。这种独特的新状态不遵循通常控制电子或原子行为的量子统计，而是符合所谓的非阿贝尔统计。最近，在制造一维（1D）结构方面取得了令人印象深刻的实验进展，使得依赖于零偏峰的非阿贝尔状态的间接检测成为可能。这项工作将使在未来的量子计算中使用非阿贝尔状态成为可能。技术摘要：本项目开辟了在二维（2D）外延平台上创建和操纵拓扑激励的新途径。它结合了二维电子气体（2DEG）中的邻近感应超导性和由磁场旋转和/或纳米磁体的边缘场产生的磁性结构。这些磁性纹理在2DEG中设计了一个有效的哈密顿量，支持马约拉纳零模式的创建。二维几何结构克服了一维马约拉纳零模式的障碍，允许实现环形、交叉和t型结的编织和融合，为拓扑量子计算开辟了一条新的道路。我们的基础研究成果将为建立一个新的可扩展的拓扑激励研究平台提供重要的实验进展。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical Abstract: Physical properties of a semiconductor are modified when it is placed in proximity to a superconducting material. Interfacing semiconductors with superconductors in a controlled way allows to control such novel properties. When the conditions at the interface are right, new types of behavior may emerge. For example, emergent states known as Majorana zero modes can form at this interface, and manifest as a specific measurement feature called zero-bias peak. Such unique new states do not follow the usual quantum statistics governing the behavior of electrons or atoms, but rather conform to so-called non-Abelian statistics. Recently, impressive experimental progress in fabricating one-dimensional (1D) structures has led to indirect detection of such non-Abelian states relying on zero-bias peak. This work will enable using the non-Abelian states in future quantum computing.Technical Abstract: This project takes a new path to create and manipulate topological excitations on a two-dimensional (2D) epitaxial platform. It combines proximity-induced superconductivity in a 2D electron gas (2DEG) with magnetic textures originating from rotation of the magnetic field and/or fringing fields of nano-magnets. These magnetic textures engineer an effective Hamiltonian in the 2DEG that supports the creation of Majorana zero modes. The 2D geometry overcomes obstacles of one-dimensional Majorana zero modes allowing realization of ring, cross and T-junctions for braiding and fusing, opening a new path to topological quantum computing. The results of our fundamental research will provide important experimental advances to establish a new scalable platform to study topological excitations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.