Excellence in Research: First Principles Defect Engineering of Plasmonic Diluted Magnetic Semiconducting Oxide Nanocrystals

卓越研究：等离子体稀释磁性半导体氧化物纳米晶体的第一原理缺陷工程

基本信息

批准号：
2013854
负责人：
Mogus Mochena
金额：
$ 35万
依托单位：
Florida Agricultural and Mechanical University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-15 至 2024-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2013854&HistoricalAwards=false
关键词：
Excellence Research First Principles Defect

项目摘要

Non-technical SummaryThis HBCU-UP award supports theoretical and computational research to simulate and predict novel quantum dots on the one hand and to develop a multidisciplinary computational physics program within the Department of Physics on the other. Quantum dots have been termed artificial atoms or molecules depending on their size and composition. They range in size from 1 – 100 nm in diameter and in numbers of atoms from hundreds to tens of thousands. While the composition and properties of atoms are predetermined by nature, the properties of artificial atoms or molecules can be manipulated by varying their size and composition. Myriad opportunities exist to create novel nanostructures, and this makes quantum dots a rich system for investigating fundamental physics as well as for technological applications.The project seeks to merge two different kinds of quantum dots, namely plasmonic quantum dots and diluted magnetic quantum dots. Plasmonic materials are based on collective motions of electrons in solids known as plasmons. These materials had been studied mostly on the macroscopic scale with classical electromagnetism theory until recently. A new property of plasmons known as localized surface plasmons was discovered on the surface of quantum dots a decade ago. The existing approach of classical physics has to be replaced with quantum mechanics in order to understand the emergent phenomena. But developing a new theory for a finite system such as a quantum dot requires computational methodology, since the finiteness breaks the translational symmetry often invoked to solve problems for periodic systems. The PI will apply quantum-mechanical as well as semi-classical computational techniques to study a range of plasmonic quantum dots. These dots are expected to have application in photonics and optoelectronics. On a separate track, the project will investigate the plasmonic materials for the onset of ferromagnetism when doped with a dilute amount of magnetic ions. These materials are of interest in their own right for applications to prospective quantum computers and spintronics at large. Eventually, the two tracks will be combined to see the possibility of a multifunctional novel material. The award will support the establishment of a computational physics program. The PI will work with computational physicists and computer scientists to offer courses modelled after a similar program at the Texas Advanced Computing Center (TACC). TACC resources will be used to train the students on high-performance computing platforms. During their senior year, the students will work on research problems. The course offerings and training are expected to prepare the students for jobs in high tech industry or to continue their research and computational experience into graduate school. In addition, the award will support a graduate student. The PI will be involved in outreach programs to community colleges and high schools to increase the number of students in the computational physics program.Technical SummaryThis proposal aims to design multifunctional semiconducting oxide quantum dots by co-doping them with magnetic and non-magnetic dopants. The project will have three thrusts:1) Semiconducting nanoplasmonic oxides: First-principles calculations with density functional theory and the kinetic Monte Carlo technique will be performed to develop new physical models that could address i) the effect of band-to-band transitions, ii) localization of carriers, iii) ligand and proximal effects, iv) quantum confinement effects for small-sized quantum dots, and v) fewer carriers than those of noble metal nanocrystals that are well described by the Drude-Lorentz model.2) Semiconducting oxide quantum dots doped with TMs: The evolution of ferromagnetism in semiconducting oxides is controversial in general because of the large number of competing parameters involved in the synthesis. A detailed study of the electronic and magnetic structures of transition-metal-doped semiconducting oxide quantum dots throughout a wide parameter space which covers the incorporation of varying amounts of dopant impurities, vacancies, and crystalline defects such as interstitials will be conducted.3) Plasmonic diluted magnetic semiconducting oxide quantum dots: After steps 1) and 2) have been undertaken, the combined system will be studied. The nanoplasmonic oxides will be doped with dilute amounts of transition metal atoms and the diluted magnetic oxide quantum dots with non-magnetic donors. Electronic and magnetic structures of the combined system will be compared to results from 1) and 2). The research will involve a graduate student and introduction of undergraduates to research protocols. In tandem with the research, a computational physics track will be launched that will train undergraduate students in scientific supercomputing. The computational physics program is expected to increase the number of physics majors. The PI will be also involved in outreach programs to community colleges and high schools.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 HBCU-UP 奖项一方面支持理论和计算研究，以模拟和预测新型量子点，另一方面在物理系内开发多学科计算物理项目。量子点被称为人造原子或分子。取决于它们的大小和成分。它们的直径范围为 1 – 100 nm，原子数量为数百到数万。虽然原子的成分和性质是由自然界预先决定的，但原子的性质是人造的。可以通过改变原子或分子的大小和成分来操纵它们，这使得量子点成为研究基础物理和技术应用的丰富系统。该项目旨在融合两种不同类型的量子。点，即等离子体量子点和稀释磁性量子点，是基于固体中电子的集体运动（称为等离子体激元）这些材料主要在宏观尺度上进行了经典研究。电磁理论直到十年前才在量子点表面发现了一种称为局域表面等离子体的新特性，为了理解新兴现象，现有的经典物理学方法必须被量子力学所取代。有限系统（例如量子点）的新理论需要计算方法，因为有限性打破了通常用来解决周期系统问题的平移对称性。PI 将应用量子力学和半经典。研究一系列等离子体量子点的计算技术预计将在光子学和光电子学中得到应用，该项目将研究掺杂少量磁性离子时等离子体材料的铁磁性。这些材料本身对未来的量子计算机和自旋电子学的应用很感兴趣，最终，这两个方向将被结合起来，以看到多功能新型材料的可能性。 PI 将与计算物理学家和计算机科学家合作，提供仿照德克萨斯高级计算中心 (TACC) 的类似项目的课程，该资源将用于在高性能计算平台上培训学生。在大四期间，学生将致力于研究问题，课程设置和培训预计将为学生在高科技行业的工作做好准备，或在研究生院继续他们的研究和计算经验。 PI将参与其中。在社区大学和高中的推广计划中，以增加计算物理课程的学生数量。技术摘要该提案旨在通过将磁性和非磁性掺杂剂共掺杂来设计多功能半导体氧化物量子点。该项目将有三个。推力：1) 半导体纳米等离子体氧化物：将利用密度泛函理论和动力学蒙特卡罗技术进行第一性原理计算，以开发新的物理模型，以解决 i) 的影响带间跃迁，ii) 载流子的局域化，iii) 配体和邻近效应，iv) 小尺寸量子点的量子限制效应，以及 v) 比德鲁德充分描述的贵金属纳米晶体更少的载流子-洛伦兹模型。2）掺杂TM的半导体氧化物量子点：半导体氧化物中铁磁性的演化总体上是有争议的，因为合成中涉及的大量竞争参数在广泛的参数空间中详细研究了过渡金属掺杂的半导体氧化物量子点的电子和磁性结构，其中涵盖了不同数量的掺杂剂杂质、空位和晶体的掺入。 3）等离子体稀释磁性半导体氧化物量子点：在进行步骤1）和2）之后，将研究组合系统。纳米等离子体氧化物将掺杂少量过渡金属原子，并且具有非磁性供体的稀释磁性氧化物量子点将与 1) 和 2) 的结果进行比较。与该研究一起，将启动一个计算物理课程，该课程将培训本科生进行科学超级计算，预计将增加物理专业的数量。 PI 还将参与社区大学和高中的推广计划。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。