EAGER: Quantum Dynamics of Spin in Single-Molecule Magnets

非技术摘要：该提案旨在巩固一个综合的实验和教育框架，用于研究，理解和传播详细介绍单分子磁体量子磁性的知识。对纳米材料量子特性的控制导致了新的新兴技术的出现，如量子信息和计算过程。纳米尺度分子系统在超高密度集成和量子信息处理方面具有巨大的潜力，这是基于本项目研究的基本性质的技术。沿着这些思路，本项目将推进一系列实验实现，以研究光子与分子磁体系综之间的耦合，以应用于量子信息、分子自旋电子学和相关的新兴量子技术。这个高风险/高回报的项目将打开大门，探索量子动力学的自旋在能量和温度范围内从未探索过。拟议的研究与主要研究者小组正在进行的一系列教育活动紧密结合。研究生和本科生将接受无机化学与基础物理和应用物理之间的接口培训，并接触主要研究者多年来建立的大型跨学科国际合作网络。技术摘要：该项目旨在巩固一个综合的实验和教育框架，用于研究、理解和传播详细介绍单分子磁体在广泛实验条件下的磁特性的知识。该项目的主要科学目标是研究单分子和单离子磁体中光-物质相互作用的性质，实现对分子自旋的量子相干控制。该计划的主要科学目标是研究分子纳米磁体中光-物质相互作用的性质，并实现对分子自旋的量子相干控制。特别是，我们的目标是相干控制的时间演化的自旋的分子后，应用快速脉冲微波辐射在弱耦合制度在亚开尔文温度（50 mK），偶极移相将被抑制，由于极化的自旋浴，而不需要大的磁场。这将打开一个窗口，在一个能量范围内（频率10 GHz，磁场1 T）的SMM单晶退相干的基本来源，以前从未探索过。PI已经在先前的NSF-DMR支持下证明了该技术。这种毫开尔文时间分辨EPR能力在全球范围内是独一无二的，将允许探索与系统的固有各向异性直接相关的SMM和西姆斯中的动力学效应，使PI的团队在该领域处于领先地位。这是一个高风险高回报的项目，因为概念验证实验结果仅在标准光谱自旋标记中获得。挑战在于将这些研究扩展到分子纳米磁体的单晶体，这将需要识别可行的候选样品，并且将依赖于除PI的新技术（偶极移相）可以消除的移相源之外的移相源的弱效应。然而，如果该技术与分子磁体一起工作，它将打开一扇令人兴奋的大门，探索在以前从未探索过的能量和温度范围内自旋的量子动力学（高奖励），允许探索低磁场的领域时，系统响应的内在和复杂的各向异性对称性，使分子纳米磁体独特。这个奖项反映了NSF的法定使命，并已被认为值得支持，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。

Non-technical abstract:This proposal seeks to consolidate an integrated experimental and educational framework for the study, understanding, and dissemination of knowledge that details the quantum magnetic properties of single-molecule magnets. The control of quantum properties of nanoscale materials has led to the appearance of new emerging technologies, such as quantum information and computation processes. Nanoscale molecular systems have great potential for ultra-high density integration and quantum information processing, which are technologies that base on the fundamental properties studied in this project. Along these lines, this project will advance a conjunction of experimental realizations to study the coupling between photons and ensembles of molecular magnets, in view of application in quantum information, molecular spintronics and related emerging quantum technologies. This high risk/high reward project will open the door to explore the quantum dynamics of spin in an energy and temperature range never explored before. The proposed research is strongly integrated with a series of educational activities ongoing in the group of the principal investigator. Graduate and undergraduate students will be trained at the interface between inorganic chemistry and fundamental and applied physics, and exposed to a large, interdisciplinary and international net of collaborations that the principal investigator has established over many years.Technical abstract:This project seeks to consolidate an integrated experimental and educational framework for the study, understanding, and dissemination of knowledge that details the magnetic properties of single-molecule magnets under a broad range of experimental conditions. The main scientific goal of this project is to study the nature of light-matter interaction in single-molecule and single-ion magnets and achieve quantum coherent control over the molecular spin. The main scientific goal of this proposal is to study the nature of light-matter interaction in molecular nanomagnets and achieve quantum coherent control over the molecular spin. In particular, the objective is to coherently control the time evolution of the spin of molecules upon application of fast pulsed microwave irradiation in the weak coupling regime at sub-Kelvin temperatures (50 mK) for which dipolar dephasing will be suppressed due to polarization of the spin bath without the need of large magnetic fields. This will open a window into the fundamental sources of decoherence in single crystals of SMMs in an energy range (frequencies 10GHz, and magnetic fields 1T) never before explored. The technique has already been demonstrated by the PI under prior NSF-DMR support. This milli-Kelvin time-resolved EPR capability is unique worldwide and will allow exploring dynamical effects in SMMs and SIMs directly associated to the intrinsic anisotropy of the system, placing the PI’s group in a leading position within the field. This is a high risk-high reward project in that proof-of-concept experimental results have only been obtained in standard spectroscopic spin markers. The challenge resides in expanding these studies into single crystals of molecular nanomagnets, which will require identification of viable candidate samples and will rely on weak effects of dephasing sources other than the one that can be eliminated with the PI’s new technique (dipolar dephasing). However, if the technique works with molecular magnets, it will open an exciting door to explore the quantum dynamics of spin in an energy and temperature range never explored before (high reward), allowing exploring a realm of low magnetic fields when the systems respond to the intrinsic and complex anisotropy symmetries that make molecular nanomagnets unique.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.