Towards Spin-based Quantum Computing in the Solid State: Tomography of a Spin Node

利用纳米物理系统的量子行为是一个广泛的跨学科努力的中心，由各种信息处理和安全通信应用的承诺驱动。性能提升和复杂性增加的前景推动了人们对现有或新功能（特别是量子信息处理（QIP）协议）的新设备以及超越现有技术的系统架构新范式的兴趣。基于由单个顺磁掺杂剂和相邻的核和电子自旋形成的固态“自旋配合物”的实现特别重要，因为基于自旋的量子技术很好地克服了缩放障碍。然而，组装原子相同的自旋簇在不久的将来是不可能的，这就需要新的协议来精确确定单个节点的空间结构，并有选择地处理复合体中的单个自旋。与这些想法一致，这项拨款阐明了最先进的纳米级技术和新颖的自旋操纵方案，以解决所谓的金刚石中NV中心附近的核自旋相对耦合网络，可以说是未来自旋电子和QIP设备最有前途的平台之一。我们努力的基础是电路的概念，该概念被配置为利用逻辑单元之间的原子尺度差异，以便以最佳方式处理量子信息。利用多维光谱和高分辨率成像方案，将有可能以类似于解决复杂分子结构的方式揭示给定节点的核自旋网络中的结构和连通性。这些信息对于识别和利用长寿命的核记忆，或者实现量子校正协议至关重要，而不需要额外的、特别的耦合接口。除了技术和科学优势外，我们的工作预计将具有广泛的教育成果，因为它将为学生提供独特的跨学科科学培训和与合作实验室网络互动的能力。这些伙伴关系不仅将提供一个广泛的传播平台，而且还将使PI能够推进正在进行的外展项目，这些项目旨在通过暑期活动为贫困学生提供有意义的研究经验。这些计划在城市学院获得了特殊的意义，这是一所少数族裔服务机构，拥有独特的城市学生群体。利用现有的各种招聘渠道，该项目的教学、指导和职业咨询部分将真正扩大参与，同时鼓励科学界代表性不足的群体在学术界和工业界追求科学事业。

Harnessing the quantum behavior of nanoscopic physical systems is at the center of a broad cross-disciplinary effort driven by the promise of various applications for information processing and secure communication. The prospect of performance gains and increased complexity is driving interest in new devices for existing or new functions (particularly, quantum information processing (QIP) protocols) as well as new paradigms for system architectures beyond present technology. Implementations based on solid-state "spin complexes" formed by individual paramagnetic dopants and neighboring nuclear and electronic spins are of particular importance because spin-based quantum technology is well positioned to overcome the obstacles to scaling. Assembling atomically identical spin clusters, however, is unlikely in the near term future, making new protocols necessary to precisely determine the spatial structure of an individual node and selectively address single spins within the complex. In line with these ideas, this grant articulates state-of-the-art nanoscale technology and novel spin manipulation schemes to resolve the network of relative couplings of nuclear spins in the vicinity of the so-called NV center in diamond, arguably one of the most promising platforms for future spintronic and QIP devices. Underlying our effort is the notion of circuits configured to exploit the atomic scale differences between logic units so as to process quantum information in optimal ways. Capitalizing on multi-dimensional spectroscopy and high-resolution imaging schemes, it will be possible to expose the structure and connectivity within the nuclear spin network of a given node in ways resembling the solving of a complex molecular structure. Such information will be crucial to identifying and exploiting long-lived nuclear memories, or to implementing quantum correction protocols without resorting to additional, ad-hoc coupling interfaces. Besides the technological and scientific advantages, our work is expected to have a broad educational outcome because it will offer students a unique inter-disciplinary scientific training and the ability to interact with a network of collaborating labs. These partnerships not only will provide a broad dissemination platform but also will allow the PI to advance ongoing outreach programs designed to provide meaningful research experiences to underprivileged students through summer activities. These plans gain special meaning at City College, a minority serving institution with a uniquely diverse population of inner-city students. Capitalizing on the various recruitment channels at hand, the teaching, mentoring and career counseling components of this project will truly broaden participation, while encouraging groups underrepresented in the sciences to pursue scientific careers both in academia and in industry.