Spectroscopic Investigations of Molecular Quantum Materials. Probing Spin-Phonon Couplings and Intermolecular Magnetic Interactions

在这个由化学系化学结构、动力学和机理B计划资助的项目中，田纳西大学化学系薛子玲教授正在研究分子量子材料在超高密度数据存储、量子计算和低温磁制冷方面的潜在应用。预计这种材料的存储容量将比目前的存储材料大得多，这可能会导致更高效的计算机和制冷设备。该项目的具体目标是探索材料的性能，以确定影响其性能的因素。该项目是跨学科的，涵盖无机、物理和材料化学。它为学生提供了在国家实验室进行研究的不同寻常的机会，这有助于拓宽他们的教育背景和培训。PI还致力于吸引高中生考虑攻读科学专业，重点是来自低收入家庭的潜在第一代大学生。缓磁驰豫是分子量子材料相关应用中的关键特性。目前的研究工作主要集中在大各向异性和慢弛豫化合物的设计和制备上。对于自旋-声子耦合和分子间磁相互作用的本质，人们还知之甚少，这也是导致磁弛豫的主要因素。在这个项目中，分子量子材料将使用几种非传统的光谱来研究，以回答以下问题：(I)四维(4D)非弹性中子散射(INS)能否揭示分子化合物中的自旋-声子耦合？(Ii)磁峰对INS中中子散射矢量的独特依赖性能否被用来探测分子间的磁性相互作用？(Iii)远红外(IR)、拉曼、高场电子顺磁共振(EPR)、脉冲EPR和INS在多大程度上可以用于研究自旋-声子耦合？(Iv)开发有效的量子比特(量子比特)需要哪些独特的自旋-自旋弛豫特性？在解决这些根本问题方面的进展预计将是化学努力开发新系统的重要一步，这些系统有可能用作量子计算或相关量子材料应用的量子比特。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, funded by the Chemical Structure, Dynamics & Mechanism B Program of the Chemistry Division, Professor Ziling Xue of the Department of Chemistry at the University of Tennessee is investigating molecular quantum materials with potential applications in ultra-high density data storage, quantum computation, and cryogenic magnetic refrigeration. Such materials are expected to have much larger storage capacities than the current storage materials, potentially leading to much more efficient computers and refrigeration devices. The specific goal of this project is to probe properties of the materials to identify the factors responsible for their performance. The project is interdisciplinary, covering inorganic, physical, and materials chemistries. It offers students unusual opportunities to conduct research at a national laboratory, which serves to broaden their educational background and training. The PI also works to attract high school students to consider pursuing studies in science with a particular emphasis on potential first generation college students from low income families .Slow magnetic relaxation is a critical property in applications related to molecular quantum materials. Current research efforts have been mostly focused on the design and preparation of compounds with large anisotropies and slow relaxation. There is relatively little understanding of the nature of spin-phonon couplings and intermolecular magnetic interactions, which are also main factors contributing to magnetic relaxation. In this project, molecular quantum materials will be studied using several unconventional spectroscopies to answer the following questions: (i) Can four-dimensional (4D) inelastic neutron scattering (INS) reveal spin-phonon coupling in molecular compounds? (ii) Can a magnetic peak’s unique dependence on the neutron scattering vector in INS be used to probe intermolecular magnetic interactions? (iii) To what degree can the combined use of far-infrared (IR), Raman, high-field electron paramagnetic resonance (EPR), pulsed EPR, and INS be used to study spin-phonon coupling? (iv) What are unique spin-spin relaxation properties are needed to develop effective quantum bits (qubits)? Progress in addressing these fundamental questions is expected to be an important step in the effort of the chemistry to develop new systems that have the potential to serve as quantum bits for quantum computing or related quantum materials applications.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.