Postdoctoral Fellowship: MPS-Ascend: Controlling the spin and charge of color centers in diamond under cryogenic conditions

钻石是一种非凡的仅由碳构成的材料。金刚石是最硬的天然材料之一，与许多电绝缘体不同，它是热的良导体。这些特性导致了许多工业应用，例如用于磨削，钻孔和切割的磨料。金刚石还拥有一个敏感的磁场和电场探测器：氮空位（NV）中心。NV中心可用于感应磁性物体，并有可能用作量子计算的量子比特（量子位）。金刚石中NV中心的研究大多是在室温和环境条件下进行的。低温条件大大改变了其光学特性，为NV中心的控制和读出创造了新的机会。在MPS-Ascend项目中，PI将使用他博士工作期间开发的仪器来研究低温下NV自旋、光学和电子特性之间的相互作用。PI将把他的研究与教育活动结合起来，这些活动建立在PI作为教育者的经验基础上，包括对本科生和初中毕业生的指导以及在当地高中的推广活动。由于局部应变对近红外光谱的影响所引起的并发症，低温操作近红外中心在传感领域受到的关注相对较少。PI计划进行一项系统的调查，以阐明晶体应变与光学循环之间的相互作用。这些研究将由PI开发的具有多色激发能力的低温显微镜实现。该仪器集成了磁共振和原子力显微镜功能，可以结合实现NV扫描探针实验。活动将集中在低温条件下NV显示的窄自旋选择性光学跃迁上，主要有两个目标：(i)开发增强形式的NV自旋读出，重点是应用于传感；（ii）研究共振光激发下的NV电荷态动力学，着眼于亚衍射光存储器。计划中的研究还将实现有效的自旋到电荷转换方案，作为获得增强的NV灵敏度的替代方案。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。

Non-technical DescriptionDiamond is a remarkable material made only of carbon. Diamond is one of the hardest natural materials and, unlike many electrical insulators, it is a good conductor of heat. These properties have led to many industrial applications, such as an abrasive used in grinding, drilling, and cutting. Diamond also hosts a sensitive detector of magnetic and electric fields: the nitrogen vacancy (NV) center. NV centers can be used to sense magnetic objects and have potential for use as quantum bits (qubits) for quantum computing. Most work on NV centers in diamond has been done at room temperature under ambient conditions. Cryogenic conditions substantially alter its optical properties, creating new opportunities for control and readout of NV centers. In this MPS-Ascend project, the PI will use instrumentation developed during his doctoral work to investigate the interplay between the NV spin, optical, and electronic properties at low temperatures. The PI will integrate his research with educational activities that build on the PI’s experience as an educator, including mentorships of undergraduates and junior graduates as well as outreach activities in local high schools.Technical DescriptionCryogenic manipulation of NV centers has received relatively little attention in the context of sensing, due to complications deriving from the impact of local strain on the NV optical spectrum. The PI plans to carry out a systematic investigation that will shed light on the interplay between crystal strain and optical cyclicity. These studies will be enabled by a cryogenic microscope developed by the PI that has multi-color excitation capabilities. This instrumentation integrates magnetic resonance and atomic force microscopy capabilities that can be combined to implement NV scanning probe experiments. Activities will center on the narrow, spin-selective optical transitions NVs display in the cryogenic regime with two main goals: (i) develop enhanced forms of NV spin readout with emphasis on applications to sensing, and (ii) study the NV charge state dynamics under resonant optical excitation with an eye on sub-diffraction optical memories. The planned studies will also enable effective spin-to-charge conversion schemes as an alternative to attaining enhanced NV sensitivity.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.