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

非技术摘要：当半导体被放置在超导材料附近时，其物理性质被改变。以受控的方式将半导体与超导体连接起来，可以控制这种新的性质。当界面上的条件合适时，可能会出现新的行为类型。例如，被称为Majorana零模的出射状态可以在这个界面上形成，并表现为一种称为零偏压峰的特定测量特征。这种独特的新状态并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，在制备一维(1D)结构方面取得了令人印象深刻的实验进展，使得依赖于零偏压峰的这种非阿贝尔态的间接检测成为可能。这项工作将使得在未来的量子计算中使用非阿贝尔态成为可能。技术摘要：本项目采用了一条在二维(2D)外延平台上创建和操纵拓扑激发的新途径。它将二维电子气(2DEG)中的邻近感应超导电性与源于纳米磁体磁场和/或边缘磁场旋转的磁性织构结合在一起。这些磁性织构在2DEG中设计了一个有效的哈密顿量，它支持Majorana零模的创建。2D几何克服了一维Majorana零模的障碍，允许实现环形、十字和T型结的编织和融合，为拓扑量子计算开辟了一条新的途径。我们的基础研究成果将提供重要的实验进展，以建立一个新的可扩展的平台来研究拓扑激发。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.