Light Modulation of Charge Transfer-Induced Spin-Transfer Processes in Single Molecules for Quantum Information Science

在该项目中，由化学部的化学结构，动力学机制B计划资助，内华达大学里诺分校化学系的Natia Frank教授正在开发在暴露于光时改变颜色的化学复合物（光致变色）。& 这些复合物也表现出随着光的磁性变化。在施加外部刺激（光、电场或磁场）时改变磁性、颜色或电荷的功能材料是用于计算机、自旋电子器件和用于量子信息科学的传感器的非易失性存储器技术的发展的核心。 在这项研究中设计和开发的材料可用作量子计算，通信和传感器中的“量子比特”。一般来说，一个量子比特至少有两个定义明确的状态，可以独立地准备和寻址。量子比特可以与刺激相互作用，产生无限数量的中间状态，从而为量子层面的数据处理，存储和传感带来令人兴奋的新可能性。 该项目的近期目标是为分子量子比特创建一种通用策略，该策略可以在环境条件下用光控制，以使嵌入式电阻存储设备和传感器能够显着降低能源需求。该研究位于化学，物理和材料科学的界面，为STEM科学的学生提供多学科培训。该研究项目还将作为一个平台，社区可持续学习和改进教学实践的发展，以提高不同群体在STEM领域的成功。社区参与的学习活动将涉及研究助理与初中和高中学生的结构化辅导活动，并在本科课堂上为不同的学习者制定新的教学策略。将光致变色配体偶联到电致变色金属配合物上的概念是控制光门功能材料的电子结构和寿命的策略。光致变色螺恶嗪配体具有两个可以光学门控的电子态。当耦合到具有两个基态电子态的电子自旋的钴半醌时，产生四态电子系统。这种耦合，一个光异构化诱导自旋电荷激发态（PISCES）的过程，可能会导致一个强大的战略，光学门控自旋态。然而，金属中心和光致变色状态之间的电子耦合是复杂的，并且对阐明电子耦合的主要机制的基础研究是将这种策略扩展到其他基于自旋的系统的核心。该项目将确定在可用作自旋量子比特的广泛类别的电子自旋金属络合物中控制PISCES过程的基本电子和结构因素;评估光门控金属络合物的自旋动力学和退相干时间，以确定这类自旋量子比特的设计原则;并确定分子间相互作用对PISCES过程，自旋寿命和纳米结构薄膜和表面的退相干的影响。该项目的成果可以为加速基于量子架构的低能耗传感器和计算应用的关键电子耦合参数提供基本见解。该奖项反映了NSF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。

In this project, funded by the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, Professor Natia Frank of the Department of Chemistry at the University of Nevada-Reno is developing chemical complexes that change color on exposure to light (photochromic). These complexes also exhibit changes in magnetic properties with light. Functional materials that change magnetism, color or charge upon application of external stimuli (light, electric field, or magnetic field) are central to the development of non-volatile memory technologies for computers, spintronics devices, and sensors for quantum information science. The materials designed and developed in this research can be used as "qubits" in Quantum computing, communications, and sensors. In general, a qubit possesses at least two well-defined states that can be prepared and addressed independently. Qubits can interact with stimuli to generate an infinite number of intermediate states leading to exciting new possibilities for data processing, storage, and sensing at the quantum level. The immediate goal of this project is the creation of a generalized strategy for molecular qubits that can be controlled with light under ambient conditions to enable embedded resistive memory devices and sensors with significantly decreased energy demand. The research lies at the interface of chemistry, physics, and material science, providing multidisciplinary training to students in the STEM sciences. The research project will also serve as a platform for Community Engaged Learning and the development of modified teaching practices for increasing the success of diverse groups in the STEM fields. Community-engaged learning activities will involve research assistantships with structured mentoring activities for middle-school and high-school students and the development of new teaching strategies for diverse learners in the undergraduate classroom. The concept of coupling optically-bistable photochromic ligands to electronically-bistable metal complexes is a strategy for controlling the electronic structure and lifetime of optically-gated functional materials. Photochromic spirooxazine ligands have two electronic states that can be gated optically. When coupled to an electronically bistable cobalt semiquinone with two ground state electronic states, a four-state electronic system is generated. This coupling, a Photoisomerization Induced Spin Charge Excited State (PISCES) process, could lead to a powerful strategy for optically gating spin states. The electronic coupling between metal center and photochrome states, however, is complex, and fundamental studies towards elucidating the primary mechanism of electronic coupling are central to the expansion of this strategy towards other spin-based systems. This project will determine the fundamental electronic and structural factors that govern PISCES processes in a broad class of electronically bistable metal complexes that can serve as spin-qubits; evaluate the spin dynamics and decoherence times for optically-gated metal complexes to determine design principles for this class of spin-based qubits; and determine the effect of intermolecular interactions on PISCES processes, spin lifetimes and decoherence in nanostructured thin films and surfaces. The results of this project could provide fundamental insight into the electronic coupling parameters critical for the acceleration of low-energy demand sensor and computing applications based on quantum architectures.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.