Quantum networks play an indispensable role in quantum information tasks such as secure communications, enhanced quantum sensing, and distributed computing. Among the most mature and promising platforms for quantum networking are nitrogen-vacancy centers in diamond and other color centers in solids. One of the challenges in using these systems for networking applications is to controllably manipulate entanglement between the electron and the nuclear spin register despite the always-on nature of the hyperfine interactions, which makes this an inherently many-body quantum system. Here, we develop a general formalism to quantify and control the generation of entanglement in an arbitrarily large nuclear spin register coupled to a color center electronic spin. We provide a reliable measure of nuclear spin selectivity, by exactly incorporating into our treatment the dynamics with unwanted nuclei. We also show how to realize direct multipartite gates through the use of dynamical decoupling sequences, drastically reducing the total gate time compared to protocols based on sequential entanglement with individual nuclear spins. We quantify the performance of such gate operations in the presence of unwanted residual entanglement links, capturing the dynamics of the entire nuclear spin register. Finally, using experimental parameters of a well-characterized 27 nuclear spin register device, we show how to prepare with high fidelity entangled states for quantum error correction.
Hyperfine spectroscopy and nuclear spin control of dark defects in diamond
Massachusetts Institute of Technology（麻省理工学院）；Quantum Innovation Centre, Agency for Science, Technology and Research（科学技术研究局量子创新中心）；University of Waterloo（滑铁卢大学）
Efficient Assembly of a Defect-Free Quantum Register of 1024 Neutral-Atom Qubits
Technische Universität Darmstadt（达姆施塔特工业大学）；Helmholtz Forschungsakademie Hessen für FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung（黑森FAIR亥姆霍兹研究院，GSI重离子研究中心）
Optical detection of the electron spin resonances of G centers in silicon
Laboratoire Charles Coulomb, Université de Montpellier and CNRS（夏尔·库隆实验室，蒙彼利埃大学与法国国家科学研究中心）；Division of Applied Quantum Systems, Felix-Bloch Institute for Solid-State Physics, University Leipzig（莱比锡大学费利克斯·布洛赫凝聚态物理研究所应用量子系统部）；Department of Physics, University of Oslo（奥斯陆大学物理系）；CNRS, Aix-Marseille Université, Centrale Marseille, IM2NP, UMR 7334（法国国家科学研究中心，艾克斯-马赛大学，马赛中央理工学院，IM2NP联合研究实验室）；Luminy Biotech（吕米尼生物技术公司）；Univ. Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS（格勒诺布尔阿尔卑斯大学，法国原子能和替代能源委员会，格勒诺布尔国立理工学院，IRIG，PHELIQS）；Institut Universitaire de France（法兰西学院）
Localization and coherent control of 25 nuclear spins in Silicon Carbide
University of Stuttgart（斯图加特大学）；Eötvös Loránd University（罗兰大学）；MTA–ELTE Lendület “Momentum” NewQubit Research Group（匈牙利科学院-罗兰大学Lendulet“动量”NewQubit研究组）；Leibniz-Institute of Surface Engineering (IOM)（莱布尼兹表面工程研究所）；Linköping University（林雪平大学）；Max Planck Institute for solid state physics（马克斯·普朗克固体物理研究所）
Quantum-network nodes with real-time noise mitigation using spectator qubits
QuTech, Delft University of Technology（代尔夫特理工大学 QuTech）；Kavli Institute of Nanoscience Delft, Delft University of Technology（代尔夫特理工大学 卡弗里纳米科学研究所）；Physikalisches Institut, ZAQuant, University of Stuttgart（斯图加特大学 ZAQuant 第三物理研究所）
ST 1心是金刚石中的一个点缺陷，具有明亮的荧光，是光学自旋初始化和读出的机制。该中心在钻石量子计算中具有令人印象深刻的应用潜力，可以作为核自旋寄存器的量子总线。这是因为它具有非常高的读出对比度，并且与众所周知的氮空位中心不同，它不具有使核自旋去球的基态电子自旋。然而，它的化学结构是未知的，我们对其性质的理解存在很大的差距。本文报道了天然金刚石中ST_1心的发现。我们的实验确定了有趣的中心的光学动力学的功率依赖性，并揭示了新的电子结构。我们还提出了一个理论，它的电子-声子相互作用，我们结合以前的实验，入围可能的候选人，其化学结构。
