CAREER: Orbital-based Descriptors for Dynamical Properties of Quantum Defects

职业：基于轨道的量子缺陷动力学特性描述符

• 批准号: 2340733
• 负责人: Yuanxi Wang
• 金额: $ 54.54万
• 依托单位: University of North Texas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2029-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340733&HistoricalAwards=false
• 关键词: CAREER; Orbital; based; Descriptors; Dynamical

NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education to understand how quantum devices can be physically realized by defects in solids, as well as how to rank and optimize their performance in search of an ideal candidate. A quantum bit (qubit) – the fundamental unit in achieving quantum computation – requires a physical representation based on a quantum mechanical system with a binary degree of freedom to host its zeros and ones. Crystallographic point defects constitute one promising physical qubit platform. To qualify as an ideal defect-based qubit, a long list of performance requirements related to the defect’s physical properties need to be met. This project will focus on two such properties related to (i) how atomic vibrations affect light absorption, and (ii) how quickly defect spins can change states following light absorption. To model these properties, two sets of computer simulation methods will be developed. One set will perform accurate but computationally demanding calculations based on microscopic models, serving as reference for select defects. Another set of methods will rely on physically motivated approximations for higher computational efficiency; they will be calibrated and validated by the accurate methods and will streamline the evaluation of a wider variety of potential defect candidates. This project will benefit society and technological development by broadening the design space and delivering rational design rules for quantum devices.Integrated with research, the following educational activities will be developed. First, the PI will develop a workshop that guides high school students in reading research papers and formulating research questions in materials physics. The workshop will aim at guiding career aspirations in scientific, engineering, and mathematical disciplines and cultivating authentic research experiences in materials physics. Second, the project will develop a platform enabling high school students to generate virtual reality demonstrations of defect and crystal structures for outreach events at the Fort Worth Museum of Science and History. Third, the PI will introduce a new high performance computing module to the undergraduate computational physics curriculum at his institution. The project will also support travel to annual conferences at the Society for the Advancement of Chicanos/Hispanics and Native Americans in Science, where student experience and research outcomes will be shared with prospective Hispanic students interested in physics and inspire their careers in physics.TECHNICAL SUMMARYCrystallographic point defects constitute one promising physical platform for implementing spin-based qubits, delivering both potential scalability and long spin coherence times. As the search for ideal defect qubits advances, increasingly complex defect metrics need to be predicted and optimized. Despite recent advances in first-principles defect modeling, two dynamical properties of defects – electron-phonon coupling and intersystem crossing rates – remain hard to calculate and hard to interpret. To tackle this challenge, the PI and his team will develop orbital-based descriptors for Huang-Rhys factors (for electron-phonon coupling), excited-state spin-orbit coupling matrix elements, and singlet-triplet splitting, thereby delivering rational design rules to optimize them for qubit applications. The development of each descriptor will be accompanied by first-principles validation. Excited-state methods ranging from constrained density functional theory (DFT), time-dependent DFT, and the GW-Bethe Salpeter Equation approach will provide references, while ground-state DFT will be the basis of descriptor design. Established descriptors will be applied to a wider variety of defects and entered into a public database allowing user query, facilitating future modeling efforts.Integrated with research, the following educational activities will be developed. First, the PI will develop a workshop that guides high school students in reading research papers and formulating research questions in materials physics. The workshop will aim at guiding career aspirations in scientific, engineering, and mathematical disciplines and cultivating authentic research experiences in materials physics. Second, the project will develop a platform enabling high school students to generate virtual reality demonstrations of defect and crystal structures for outreach events at the Fort Worth Museum of Science and History. Third, the PI will introduce a new high performance computing module to the undergraduate computational physics curriculum at his institution. The project will also support travel to annual conferences at the Society for the Advancement of Chicanos/Hispanics and Native Americans in Science, where student experience and research outcomes will be shared with prospective Hispanic students interested in physics and inspire their careers in physics.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.

该奖项支持理论和计算研究和教育，以了解量子器件如何通过固体中的缺陷在物理上实现，以及如何在寻找理想的候选者时对其性能进行排名和优化。一个量子比特（qubit）——实现量子计算的基本单位——需要一个基于量子力学系统的物理表示，该系统具有二进制自由度来容纳零和一。晶体点缺陷构成了一个很有前途的物理量子比特平台。为了符合理想的基于缺陷的量子位，需要满足与缺陷的物理特性相关的一长串性能要求。该项目将重点关注两个相关的特性：(1)原子振动如何影响光吸收，(2)缺陷自旋在光吸收后改变状态的速度有多快。为了模拟这些特性，将开发两套计算机模拟方法。其中一组将根据微观模型进行精确但计算要求高的计算，作为选择缺陷的参考。另一组方法将依赖于物理动机近似，以获得更高的计算效率；它们将被精确的方法校准和验证，并且将简化对更广泛的潜在缺陷候选的评估。该项目将通过拓宽量子器件的设计空间和提供合理的设计规则来造福社会和技术发展。结合研究，将开展以下教育活动。首先，PI将开发一个研讨会，指导高中生阅读材料物理学的研究论文和提出研究问题。研讨会旨在指导科学、工程和数学学科的职业抱负，培养材料物理方面的真实研究经验。其次，该项目将开发一个平台，使高中生能够为沃斯堡科学与历史博物馆的外展活动生成缺陷和晶体结构的虚拟现实演示。第三，PI将在他所在机构的本科计算物理课程中引入一个新的高性能计算模块。该项目还将支持前往奇卡诺人/西班牙裔美国人和美国原住民科学进步协会参加年度会议，在那里学生的经验和研究成果将与对物理学感兴趣的未来西班牙裔学生分享，并激励他们在物理学方面的职业生涯。晶体点缺陷构成了一个很有前途的实现自旋量子比特的物理平台，提供了潜在的可扩展性和较长的自旋相干时间。随着对理想缺陷量子位元的研究进展，需要预测和优化越来越复杂的缺陷度量。尽管最近在第一性原理缺陷建模方面取得了进展，但缺陷的两个动力学性质——电子-声子耦合和系统间交叉率——仍然难以计算和解释。为了应对这一挑战，PI和他的团队将为Huang-Rhys因子（用于电子-声子耦合）、激发态自旋-轨道耦合矩阵元素和单态-三重态分裂开发基于轨道的描述符，从而提供合理的设计规则，以优化它们用于量子位应用。每个描述符的发展将伴随着第一原理的验证。激发态方法包括约束密度泛函理论（DFT）、时变DFT和GW-Bethe Salpeter方程方法将提供参考，而基态DFT将是描述子设计的基础。已建立的描述符将应用于更广泛的缺陷，并进入允许用户查询的公共数据库，促进未来的建模工作。结合研究，将开展以下教育活动。首先，PI将开发一个研讨会，指导高中生阅读材料物理学的研究论文和提出研究问题。研讨会旨在指导科学、工程和数学学科的职业抱负，培养材料物理方面的真实研究经验。其次，该项目将开发一个平台，使高中生能够为沃斯堡科学与历史博物馆的外展活动生成缺陷和晶体结构的虚拟现实演示。第三，PI将在他所在机构的本科计算物理课程中引入一个新的高性能计算模块。该项目还将支持前往奇卡诺人/西班牙裔美国人和美国原住民科学进步协会参加年度会议，在那里学生的经验和研究成果将与对物理学感兴趣的未来西班牙裔学生分享，并激励他们在物理学方面的职业生涯。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。