The nitrogen-vacancy (NV) center in diamond has a wide range of potential applications in quantum metrology, communications and computation. The key to its use lies in how large the optical spin contrast is and the associated fidelity of spin state readout. In this paper we propose a new mechanism for improving contrast with a spin-to-charge protocol that relies on the use of an external electrode and cryogenic temperatures to discretize the diamond conduction band for spin-selective resonant photoionization. We use effective mass theory to calculate the discrete eigenenergies in this new system and use them to formulate a new spin-to-charge protocol that involves resonant photoionization out the NV ground state into the diamond conduction band. The major sources of broadening are also addressed which guide the design of the experiment. With this mechanism we theorise an optical spin contrast that and an associated spin readout fidelity of 85%. This significant improvement can be applied to a number of cryogenic quantum technologies.
Electroluminescence from nitrogen-vacancy and interstitial-related centers in bulk diamond stimulated by ion-beam-fabricated sub-superficial graphitic micro-electrodes
Creation of Depth-Confined, Shallow Nitrogen-Vacancy Centers in Diamond With Tunable Density
Materials Department, University of California, Santa Barbara（加州大学圣塔芭芭拉分校材料系）；Division of Engineering and Applied Science, California Institute of Technology（加州理工学院工程与应用科学部）；Department of Physics, University of California, Santa Barbara（加州大学圣塔芭芭拉分校物理系）；Department of Materials Science and Engineering, Stanford University（斯坦福大学材料科学与工程系）
Tunable cavity coupling of the zero phonon line of a nitrogen-vacancy defect in diamond
我们证明了在低温下金刚石中单个氮空位色心零声子线的可调增强。使用聚焦离子束铣削制造的开放腔提供小至1.24 $μ$ m $^3$的模体积。腔体谐振的原位调谐通过压电致动器实现。在最佳耦合的全开放腔的信号从个人零声子线跃迁增强了约10倍的NV $^-$中心的总发射率增加了40%，从相同的中心在没有腔场限制的情况下相比，测量。这一结果对于利用光寻址固态自旋量子比特实现高效的自旋光子接口和可扩展的量子计算具有重要意义。
Optically-Induced Modulation and Programming of Diamond Photonic Cavities
Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL)（洛桑联邦理工学院物理研究所）；Center of Quantum Science and Engineering, Swiss Federal Institute of Technology Lausanne (EPFL)（洛桑联邦理工学院量子科学与工程中心）；Photonics Research Group, Department of Information Technology (INTEC), Ghent University - IMEC（根特大学信息技朮系光子研究组（与IMEC联合））；University of Stuttgart（斯图加特大学）
Engineering and Probing a One-Dimensional Dipolar Spin Ensemble in Diamond
University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；California Institute of Technology（加州理工学院）；Stanford University（斯坦福大学）；Harvard University（哈佛大学）；Boston University（波士顿大学）；Max-Planck-Institut für Physik Komplexer Systeme（马克斯·普朗克复杂系统物理研究所）
