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.

非技术摘要这一奖项支持计算研究和教育活动，旨在了解材料中局部瑕疵的特性，称为“点缺陷”，例如其通常位置中缺少的原子或材料中的杂质。这样的点缺陷在所有材料中无处不在，即使以微量的量存在也可能对其性质产生深远的影响。在电子设备的背景下，可以确定点缺陷，例如降低太阳能电池的效率；或功能，例如，允许调整材料的性质。缺陷本身甚至可以用作下一代量子计算机的微小量子位。点缺陷的小而稀释的性质使它们成为实验表征的挑战，因此计算模拟至关重要。但是，传统的计算方法对于关键缺陷特性的准确性有限，包括它们对外部刺激（如光或电脉冲）的反应。具有更高精度的更高级理论存在，但需要过多的计算能力才能应用于点缺陷。该项目旨在开发和利用通过“嵌入”来克服这些问题的计算工具，即，将常规方法与高级理论相结合以获得计算效率和准确性。这些新技术将使PI和他的团队能够对外部刺激激发的复杂缺陷进行前所未有的理解。 PI将应用这些嵌入方法来探索各种缺陷和宿主材料，这些缺陷和宿主材料应为包括量子计算机在内的下一代电动设备提供。该奖项还支持各个级别的计算物理教育的开发。在研究生层面，将开发一门专门针对计算凝结物理学的最先进方法的课程；本科水平，物理专业所需的计算物理类将被更改，以使其更具互动性和基于项目的互动性；在高中级别，将进行外展以提高计算素养。技术摘要奖支持研究和教育活动，旨在了解点缺陷的激发电子状态的物理学。 PI将开发用于结合密度功能理论和多体方法的量子嵌入技术，以准确捕获与电子设备和量子技术相关的缺陷中的电子相关性和兴奋。旨在改善方法学改进的项目将开发出对缺陷和散装状态之间库仑相互作用的更准确，强大的处理，以及将密度功能理论与多体方法相结合的双重计数固有的。将与基于量子蒙特卡洛的其他多体方法进行比较，以基准嵌入过程中涉及的各种近似值。此外，PI将集中在涉及缺陷和晶体晶格之间的相互作用的问题上，以确定相关的极端状态在缺陷处的光学和非放射性过程中的作用。针对的特定缺陷/宿主系统将包括基于六角形BN的基于碳的缺陷，III III组氮化物中的过渡金属以及过渡金属二色属植物中的稀土，所有这些缺陷都具有基本的兴趣，以及对常规和量子电子奖的基本兴趣，并且这些奖励的技术兴趣。在研究生层面，将开发一门专门针对计算凝结物理学的最先进方法的课程；在本科级别，物理专业所需的计算物理类将被更改，以使其更具互动性和基于项目的互动性；在高中层面，将进行外展以提高计算素养。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，被视为通过评估而被视为珍贵的支持。