Hyperpolarized Multi-Spin Systems as Qubits for Quantum Information Science

西北大学化学系的Michael R. Wasielewski教授正在研究如何控制有机分子中的电荷和自旋输运。该项目由化学系化学结构、动力学和机理b项目资助。这种控制对电子、计算机和量子信息科学（QIS）的未来至关重要。这项研究提供的对分子结构和性质的控制程度使得开发利用电子自旋变化的分子和材料成为可能，以实现未来计算机的新策略，这些新策略可能具有远远超过当前模型的速度和加密技术。Wasielewski研究小组在“课堂科学”项目（SITC）中担任志愿者，在芝加哥一个历史上服务不足且多元化的社区的一所小学里，为三、四年级学生提供服务。大约三分之一的SITC课程是多语种的，在常规课程之外，英语作为第二语言学习。西北大学的学生在同一学年志愿与同一班级的学生一起，指导和激励年轻的科学家。研究组还参加了“给预备科学家的信”项目，该项目的重点是建立贫困学校中学生和科学家之间的个人联系，以笔友的身份写信，鼓励低年级学生将科学作为职业。光生分子激发态和电子转移反应在量子信息科学（QIS）中发挥着越来越重要的作用。该项目将根据QIS领域的DiVincenzo标准解决几个目标，这对于利用多自由基组装作为针对QIS应用的自旋量子比特至关重要。Wasielewski教授和他的团队使用两个自旋选择性光物理过程来超极化电子自旋，以产生定义良好的自旋量子位元的初始量子态，并确定自旋量子位元的消相机制。然后，该团队操纵和定位特定的自旋量子比特来演示量子门，并使用微波和可见光子脉冲在两个位置之间移动（传送）自旋相干。最后，该团队建立了基于DNA发夹结构的可扩展自旋量子比特阵列的策略。他们使用激光激发产生初始超极化自旋量子比特，并使用时间分辨脉冲电子顺磁共振（pulse- epr）光谱来观察、操纵和控制这些量子比特的相干自旋状态。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。

In this project, funded by the Chemical Structure, Dynamics, and Mechanisms-B Program of the Chemistry Division, Professor Michael R. Wasielewski of the Department of Chemistry at Northwestern University is developing a fundamental understanding of how to control charge and spin transport through organic molecules. Such control is critical to the future of electronics, computers, and quantum information science (QIS). The degree of control over molecular structure and properties afforded by this research makes it possible to develop molecules and materials that take advantage of electron spin changes to implement new strategies for computer of the future that may have speeds and encryption technologies far beyond the current models. The Wasielewski research group volunteers in the Science In The Classroom program (SITC), with 3rd/4th-graders at an elementary school in an historically under-served and diverse community in Chicago. Approximately one third of the classes served by SITC are multilingual, and learn English as a second language alongside the regular curriculum. By volunteering with the same class of students for the academic year, Northwestern students mentor and inspire young scientists. The research team also participates in the program "Letters to a Pre-Scientist" which focuses on creating personal connections between middle school students from underprivileged schools and scientists to encourage the younger students to consider science as a career by writing letters as a pen pals. Photogenerated molecular excited states and electron transfer reactions are playing an increasing role in quantum information science (QIS). This project will address several goals based on what are known in the QIS field as the DiVincenzo criteria, which are essential for exploiting multi-radical assemblies as spin qubits that target QIS applications. Professor Wasielewski and his group use two spin-selective photophysical processes to hyperpolarize electron spins to generate well-defined initial quantum states of spin qubits and determine the dephasing mechanisms of the spin qubits. The team then manipulates and addresses specific spin qubits to demonstrate quantum gates and uses both microwave and visible photon pulses to move (teleport) spin coherences between two sites. Finally, the team establishes strategies for scalable spin qubit arrays based on DNA hairpin structures. They use laser excitation to generate the initial hyperpolarized spin qubits and time-resolved pulse electron paramagnetic resonance (pulse-EPR) spectroscopy to observe, manipulate and control the coherent spin states of these qubits.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.