CAREER: Correlated excited states of point defects in insulators

职业：绝缘体中点缺陷的相关激发态

• 批准号: 2237674
• 负责人: Cyrus Dreyer
• 金额: $ 57.5万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237674&HistoricalAwards=false
• 关键词: CAREER; Correlated; excited; states; point

NONTECHNICAL SUMMARYThis award supports computational research and education activities that aim to understand the properties of localized imperfections in materials, called "point defects", such as atoms missing from their usual locations or impurities within the material. Such point defects are ubiquitous in all materials and can have profound effects on their properties even if present in minute quantities. In the context of electronic devices, point defects may be detrimental, e.g., lowering the efficiency of solar cells; or functional, e.g., allowing the properties of materials to be tuned. Defects themselves can even be used as tiny quantum bits for next generation quantum computers. The small and dilute nature of point defects makes them a challenge for experimental characterization, thus computational simulations are vital. However, conventional computational methods have limited accuracy for key defect properties including their response to external stimuli like light or electrical pulses. More advanced theories with significantly better accuracy exist but require too much computational power to be applied to point defects. This project seeks to develop and utilize computational tools that overcome these issues via “embedding,” i.e., by combining the conventional methods with the advanced theories to obtain both computational efficiency and accuracy. These new techniques will allow the PI and his team to develop unprecedented understanding of complex defects excited by external stimuli. The PI will apply these embedding methods to explore a variety of defects and host materials that are promising for the next generation electrical devices including quantum computers.This award also supports the development of computational physics education at all levels. At the graduate level, a course specifically aimed at teaching state-of-the-art methods in computational condensed-matter physics will be developed; at the undergrad level, the computational physics class required for physics majors will be altered to make it more interactive and project-based; and at the high-school level, outreach will be conducted to improve computational literacy.TECHNICAL SUMMARYThis award supports research and educational activities that aim to understand the physics of excited electronic states of point defects. The PI will develop quantum embedding techniques for combining density-functional theory and many-body methods to accurately capture electron correlations and excitations in defects relevant for electronic devices and quantum technologies. Projects aimed at methodological improvements will develop more accurate and robust treatments of Coulomb interactions between defect orbitals, hybridization between the defect and bulk states, and the double-counting intrinsic to combining density-functional theory with many-body methods. Comparisons with other many-body methods based on quantum Monte Carlo will be performed to benchmark the various approximations involved in the embedding procedure. In addition, the PI will focus on problems involving interplay between the defect and the crystal lattice to determine the role of correlated excited states in optical and nonradiative processes at defects. The specific defect/host systems targeted will include carbon-based defects in hexagonal BN, transition metals in group-III nitrides, and rare earths in transition-metal dichalcogenides, all of which are of fundamental as well as technological interest for conventional and quantum electronic devices.This award also supports the development of computational physics education at all levels. At the graduate level, a course specifically aimed at teaching state-of-the-art methods in computational condensed-matter physics will be developed; at the undergrad level, the computational physics class required for physics majors will be altered to make it more interactive and project-based; and at the high-school level, outreach will be conducted to improve computational literacy.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.

非技术摘要该奖项支持旨在了解材料中局部缺陷（称为“点缺陷”）特性的计算研究和教育活动，例如原子从其通常位置缺失或材料内的杂质，此类点缺陷在所有材料和材料中都普遍存在。即使在电子设备中存在少量，也可能对其性能产生深远的影响，例如，降低太阳能电池的效率或功能，例如，允许性能。缺陷本身甚至可以用作下一代量子计算机的微小量子位，点缺陷的微小和稀薄性质使它们成为实验表征的挑战，因此计算模拟至关重要。关键缺陷特性的精度有限，包括对光或电脉冲等外部刺激的响应。存在具有更高精度的更先进的理论，但需要太多的计算能力来解决点缺陷。这些问题通过“嵌入”，即，通过将传统方法与先进理论相结合，获得计算效率和准确性，这些新技术将使 PI 和他的团队对外部刺激激发的复杂缺陷产生前所未有的理解。 PI 将应用这些嵌入方法来探索。各种缺陷和主体材料有望用于包括量子计算机在内的下一代电子设备。该奖项还支持研究生级别的计算物理教育的发展，这是一门专门针对教授最新水平的课程。 - 计算艺术方法将发展凝聚态物理学；在本科阶段，将改变物理专业所需的计算物理课程，使其更具互动性和基于项目；在高中阶段，将进行推广以提高计算素养；技术摘要该奖项支持旨在了解点缺陷激发电子态物理学的研究和教育活动，PI 将开发量子嵌入技术，将密度泛函理论和多体方法相结合，以准确捕获点缺陷中的电子相关性和激发。旨在方法改进的项目将开发更准确和更稳健的缺陷轨道之间的库仑相互作用、缺陷和体态之间的杂化，以及将密度泛函理论与许多理论结合起来的重复计算。体方法将与基于量子蒙特卡罗的许多其他体方法进行比较，以对嵌入过程中涉及的各种近似进行基准测试。此外，PI 将重点关注涉及缺陷和晶体之间相互作用的问题。晶格以确定相关激发态在缺陷处的光学和非辐射过程中的作用，目标特定缺陷/主体系统将包括六方氮化硼中的碳基缺陷、III族氮化物中的过渡金属以及过渡金属二硫属化物中的稀土。 ，所有这些对于传统和量子电子设备都具有基础和技术意义。该奖项还支持研究生阶段专门针对教学的课程的发展。将开发最先进的计算凝聚态物理方法；在本科阶段，物理专业所需的计算物理课程将进行修改，使其更具互动性和基于项目；该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。