Molecular Spin Qubits in a One-Dimensional Host

现代计算机技术的经验法则是，大约每两年，微处理器芯片上的晶体管数量就会翻一番。摩尔定律（Moore’s Law）描述了这种改进的速度，但由于各种原因，这种速度开始放缓。一个可能允许持续快速增长的新范式是量子计算。量子计算利用量子力学定律，可以解决传统计算机难以解决的某些问题。量子计算机的关键基本单位是所谓的量子比特（或量子位），类似于经典的二进制位。本研究旨在了解低维材料中的电子自旋，并基于这些电子自旋开发一种新型量子比特。两所大学在这个项目上的紧密合作，有助促进院校之间的伙伴关系。这项研究活动为参与该项目的研究生和博士后提供材料科学、量子光学和纳米光子学领域的跨学科培训。这也为培养下一代量子信息科学人才提供了一个令人兴奋的机会。单个电子的自旋是量子比特的天然候选，因为它具有存储和处理量子信息的能力。将电子自旋作为功能量子比特操作的一个关键挑战是完全控制其与外部环境的耦合。通过在量子比特材料中建立自旋光子界面，可以利用光学技术有效地操纵和读出自旋态。该方法已成功应用于块状材料中几种天然缺陷量子比特的研究。为了超越块状材料中的自旋量子比特，并允许在原子尺度上设计和控制量子比特系统，研究小组采用自下而上的方法开发集成在低维材料中的分子自旋量子比特。分子量子比特的完全合成控制使其电子结构的有效调谐成为可能。分子设计和组成控制也允许处理驱动自旋退相干的物理过程。结合第一性原理理论计算和实验研究，本研究旨在开发一种新型的分子自旋量子比特，该量子比特可以连接光子。本研究中建立的材料平台促进了对化学使能量子位及其在量子器件中的应用的理解。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。

A rule of thumb for modern computer technology is that approximately every two years, the number of transistors on a microprocessor chip doubles. This rate of improvement is described by Moore's Law, and has started to falter for a variety of reasons. One new paradigm that may permit continued rapid growth is quantum computing. Quantum computing exploits the laws of quantum mechanics and may solve certain problems that are essentially intractable with conventional computers. The key fundamental unit in a quantum computer is the so called quantum bit (or qubit), in analogy to the classical binary bit. This research aims to understand electron spins in low-dimensional materials and develop a new type of qubit based on these electron spins. A close collaboration between the two universities in this project helps promote partnership between the institutions. This research activity provides interdisciplinary training for the graduate students and postdoctoral researchers involved in this project in the areas of material science, quantum optics, and nanophotonics. It also serves as an exciting opportunity for the training of our next-generation workforce in quantum information science. The spin of a single electron is a natural candidate for qubits due to its capability to store and process quantum information. A key challenge in operating an electron spin as a functional qubit is to turn on and off its coupling to the external environment with full control. By establishing a spin-photon interface in the qubit materials, it is possible to efficiently manipulate and readout the spin states using optical techniques. This approach has been successfully implemented in studying several types of naturally occurring defect qubits in bulk materials. To move beyond spin qubits in bulk materials and allow design and control of the qubit systems on the atomic scale, the research team adopts a bottom-up approach to develop molecular spin qubits integrated in low dimensional materials. The full synthetic control of the molecular qubits enables effective tuning of their electronic structures. Molecular design and composition control also allow addressing physical processes that drive spin decoherence. Combining first-principle theory calculations and experimental studies, this research aims to develop a new type of molecular spin qubits that interface optical photons. The material platform established in this research advances understanding of chemistry-enabled qubits and their application in quantum devices.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.