Quantum Phenomena in Solids

固体中的量子现象

• 批准号: 0804564
• 负责人: Leon Balents
• 金额: $ 33万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804564&HistoricalAwards=false
• 关键词: Quantum; Phenomena; Solids

TECHNICAL SUMMARY:This award supports theoretical research and education on quantum correlation phenomena in solids. The long-term goals are to develop new materials and structures with useful functionality not currently available, and to extend the basic scientific framework to understand matter in new regimes and new phases. The research thrusts span bulk materials and heterostructures. In the former, the PI will study (1) frustration and fluctuations, and their consequences and applications; (2) magneto-electric coupling; and (3) orbital fluctuations and ordering. In the heterostructure area, the PI will consider interfaces between correlated electron materials, which are becoming a very exciting subject experimentally. The PI aims to address key outstanding questions raised by experiments in quantum magnets, multiferroics, spin-orbit coupled materials, and more complex Mott insulators. The breadth of topics is an asset to this research program; by viewing one material or structure in a broader context, the PI aims to obtain insights into the relative importance of the very many effects that might be involved. The theoretical techniques ? e.g. statistical mechanics, field theory, renormalization group, numerical methods, constraint counting ? which will be used to study competing interactions and fluctuations are also widely applicable across all these problems.Advances in the past 5 years in growing high quality atomic precision interfaces between transition metal oxides by pulsed laser deposition are remarkable. This is an extremely exciting new venue for correlation phenomena and also eventual applications building semiconductor-style heterostructures from correlated materials with their additional functionalities. The PI will carry out fundamental research aimed at elucidating the new physics occuring at these interfaces and how they differ from semiconductor heterostructures.This award supports the education of graduate students and postdocs in forefront areas of condensed matter theory. New course materials will be developed to convey the excitement of the fields to new students. NON-TECHNICAL SUMMARY:This award supports theoretical research and education to motivate and explain experiments and properties of materials. The PI will focus on particular areas which he believes are those most likely to lead to revolutionary technological impacts. These areas also advance fundamental science. Experiments reveal materials that have the necessary ingredients to become magnets, but do not exhibit magnetism. On the scale of atoms, there is a competition between the interactions that would favor aligning the fundamental building blocks of magnetism and the geometrical arrangements of the atoms. This frustrates the tendency to magnetic order. Experiments continue to deliver more examples, like the minerals Herbertsmithite and Volborthite, enabling the test of theoretical ideas that new states of matter will arise from failed magnetism. The PI will also study materials where electron charge and magnetism are closely coupled. Multiferroics are an example class of materials; they simultaneously exhibit magnetism and the electric charge analog of magnetism. The PI will also study phenomena that arise from the coupling of spin and charge in a new class of insulating materials, called topological insulators, that are rich with possibilities for new phenomena involving magnetism that arise from the motion of electrons. A recent experimental advance enables the joining of two different oxide materials, analogous to the interfaces between semiconductors that form the basis of modern electronics. In this case the oxide materials have unusual properties that arise from strong interactions between electrons. The interfaces so created are rich with the potential for new phenomena and new materials properties that may have technological impact. The PI will use sophisticated theoretical tools to understand recent experiments and predict new phenomena. The fundamental tools of advanced quantum mechanics are needed to understand experiments on these systems and to illuminate new possibilities with predictions that motivate further experiment. This work contributes to the foundations of future electronic and information technologies. This award helps provide a quality educational experience for students at the graduate and postdoctoral level.

该奖项支持固体中量子相关现象的理论研究和教育。长期目标是开发具有目前不可用的有用功能的新材料和结构，并扩展基本科学框架，以了解新制度和新阶段的物质。研究重点跨越体材料和异质结构。在前者中，PI将研究（1）挫折和波动，及其后果和应用;（2）磁电耦合;（3）轨道波动和有序。在异质结领域，PI将考虑相关电子材料之间的界面，这在实验上正成为一个非常令人兴奋的课题。PI旨在解决量子磁体，多铁性，自旋轨道耦合材料和更复杂的莫特绝缘体实验中提出的关键未决问题。主题的广度是本研究计划的一项资产;通过在更广泛的背景下查看一种材料或结构，PI旨在深入了解可能涉及的许多影响的相对重要性。理论技术？例如，统计力学，场论，重整化群，数值方法，约束计数？在过去的5年里，利用脉冲激光沉积技术在过渡金属氧化物之间生长高质量的原子级精密界面的研究取得了显著的进展。这是一个非常令人兴奋的相关现象的新场所，也是最终的应用程序，从相关材料中构建具有附加功能的半导体式异质结构。PI将开展基础研究，旨在阐明这些界面处发生的新物理以及它们与半导体异质结构的区别。该奖项支持凝聚态理论前沿领域的研究生和博士后教育。将开发新的课程材料，向新生传达该领域的兴奋。非技术性总结：该奖项支持理论研究和教育，以激励和解释材料的实验和性质。PI将专注于他认为最有可能导致革命性技术影响的特定领域。 这些领域也推动了基础科学的发展。实验揭示了具有成为磁体的必要成分的材料，但不显示磁性。在原子尺度上，相互作用之间存在竞争，有利于排列磁性的基本组成部分和原子的几何排列。这挫败了磁有序的趋势。实验继续提供更多的例子，如矿物Herbertsmithite和Volborthite，使理论思想的测试，新的物质状态将出现从失败的磁性。PI还将研究电子电荷和磁性紧密耦合的材料。多铁性材料是一类材料的例子;它们同时表现出磁性和磁性的电荷模拟。PI还将研究一类新的绝缘材料（称为拓扑绝缘体）中自旋和电荷耦合产生的现象，这些绝缘材料具有丰富的可能性，这些新现象涉及电子运动产生的磁性。最近的一项实验进展使两种不同的氧化物材料能够连接起来，类似于形成现代电子学基础的半导体之间的界面。在这种情况下，氧化物材料具有由电子之间的强相互作用引起的不寻常的性质。这样产生的界面具有丰富的新现象和新材料特性的潜力，可能会产生技术影响。PI将使用复杂的理论工具来理解最近的实验并预测新现象。需要先进量子力学的基本工具来理解这些系统上的实验，并通过激发进一步实验的预测来阐明新的可能性。 这项工作有助于奠定未来电子和信息技术的基础。该奖项有助于为研究生和博士后水平的学生提供优质的教育体验。