Quantum Phenomena in Solids

固体中的量子现象

• 批准号: 1818533
• 负责人: Leon Balents
• 金额: $ 36万
• 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: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1818533&HistoricalAwards=false
• 关键词: Quantum; Phenomena; Solids

NONTECHNICAL SUMMARYThis award supports fundamental research and education on understanding and controlling quantum properties of materials. Fundamentally, everything on Earth is governed by quantum mechanics. Yet, while quantum theory is essential to understanding the gross properties of materials, for example the existence of both metals and insulators and the phenomena of magnetism, it rarely manifests itself directly in the more macroscopic world. This project aims to bridge this gap by investigating materials in which quantum effects are unusually apparent in laboratory-scale observations. These quantum materials offer new functionalities that could not be achieved in more classical substances.The project has three main thrusts. The first targets materials that are topological and magnetic. Topological materials have a kind of internal "twist" that leads to novel conducting properties. By combining this with magnetism, control over those properties may be achieved. The second thrust focuses on emergent "quasiparticles"--objects that behave like fundamental particles of nature but modified in essential ways--with the unusual property that they are confined to fewer than the usual 3 dimensions. The third problem addressed is how to modify the properties of materials using powerful laser light. The forces from such powerful light can reorganize the electrons in a material, giving them new and interesting properties.This research involves a combination of development of theoretical techniques, numerical and analytical calculations, and close interplay with experimental studies. Graduate and undergraduate students will be involved in an essential way in the research, and will be trained broadly in analytical reasoning, mathematical methods, computation, and scientific communication, which form the basis for many careers in STEM fields, both in and out of physics.TECHNICAL SUMMARYThe award supports fundamental research and education towards understanding and controlling quantum correlations in solids. In the long term, there are two goals to the program: 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. There are three main topics: 1) Interplay of real space and momentum space topology in itinerant magnets; 2) Sub-dimensional dynamics; 3) Driven dynamics of Mott insulators. The research will be carried out using a diverse set of theoretical techniques: phenomenological modeling, statistical mechanics, field theory, ab initio simulations, many-body numerics such as Monte Carlo methods and variational wavefunctions, and symmetry analysis.In general, the intellectual merit of the research is in developing and bringing deep theoretical ideas in the theory of quantum matter to fruition in real materials. The first topic on momentum and real space topology is a next step after the maturation of the field of topological band theory, and opens the door to a rich interplay of phenomena bringing together topological aspects of electronic structure and frustrated magnetism. The second subject is both related to the frontier of topological phases and qualitatively new forms of three-dimensional matter, and also is a point where powerful theoretical techniques from one dimension can be brought to bear on difficult problems of dynamics. The final area of driven dynamics is a nascent field, in which a rapid growth of new theoretical ideas surrounding Floquet many-body problems, combined with experimental advances in ultrafast technology, offers opportunities for new physics in the solid state.Graduate and undergraduate students will be involved in an essential way in the research, and will be trained broadly in analytical reasoning, mathematical methods, computation, and scientific communication, which form the basis for many careers in STEM fields, both in and out of 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.

非技术总结该奖项支持有关理解和控制材料量子属性的基础研究和教育。从根本上说，地球上的一切都是由量子力学支配的。然而，尽管量子理论对于理解材料的总体性质是必不可少的，例如金属和绝缘体的存在以及磁性现象，但它很少直接在更宏观的世界中显现出来。这个项目旨在通过研究在实验室规模的观测中量子效应异常明显的材料来弥合这一差距。这些量子材料提供了更经典的物质无法实现的新功能。该项目有三个主要推动力。第一个目标是具有拓扑和磁性的材料。拓扑材料有一种内部的“扭曲”，这导致了新的导电性能。通过将这一点与磁性相结合，可以实现对这些性质的控制。第二个推动力集中在浮现的“准粒子”上--它们的行为像自然界的基本粒子，但在本质上进行了改造--它们的不同寻常的特性是，它们被限制在低于通常的3维空间。解决的第三个问题是如何利用强大的激光来改变材料的性质。来自如此强大的光的力可以重组材料中的电子，赋予它们新的和有趣的性质。这项研究包括理论技术的发展、数值和分析计算的结合，以及与实验研究的密切相互作用。研究生和本科生将以一种基本的方式参与研究，并将在分析推理、数学方法、计算和科学交流方面接受广泛的培训，这些知识构成了STEM领域许多职业的基础，无论是在物理领域还是在物理领域。技术总结该奖项支持基础研究和教育，以了解和控制固体中的量子关联。从长远来看，该计划有两个目标：开发具有目前无法获得的有用功能的新材料和结构，以及扩展基本的科学框架，以在新的制度和新的阶段理解物质。主要有三个主题：1)巡回磁体的实空间和动量空间拓扑的相互作用；2)亚维动力学；3)Mott绝缘子的驱动动力学。这项研究将使用一系列不同的理论技术：唯象建模、统计力学、场论、从头计算模拟、多体数值计算，如蒙特卡罗方法和变分波函数，以及对称性分析。总的来说，这项研究的智力价值在于发展和实现真实材料中量子物质理论的深刻理论想法。关于动量和真实空间拓扑的第一个主题是在拓扑带理论领域成熟之后的下一步，并打开了将电子结构的拓扑方面和受挫磁性结合在一起的现象的丰富相互作用的大门。第二个主题既与拓扑相的前沿有关，又与三维物质的定性新形式有关，也是一个可以从一个维度运用强大的理论技术来解决动力学难题的点。驱动动力学的最后一个领域是一个新兴领域，在这个领域中，围绕Floquite多体问题的新理论想法的快速增长，加上超快技术的实验进步，为固态新物理提供了机会。研究生和本科生将以基本的方式参与研究，并将接受广泛的分析推理、数学方法、计算和科学交流方面的培训，这些知识构成了STEM领域许多职业的基础，无论是在物理领域还是在物理领域。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Dynamical Signatures of Quasiparticle Interactions in Quantum Spin Chains

量子自旋链中准粒子相互作用的动力学特征

• DOI: 10.1103/physrevlett.125.187201
• 发表时间: 2020
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Keselman, Anna;Balents, Leon;Starykh, Oleg A.
• 通讯作者: Starykh, Oleg A.

Current switching of valley polarization in twisted bilayer graphene

• DOI: 10.1103/physrevb.103.115436
• 发表时间: 2021-01
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Xuzhe Ying;Mengxing Ye;L. Balents

Collective spinon spin wave in a magnetized U(1) spin liquid

• DOI: 10.1103/physrevb.101.020401
• 发表时间: 2019-04
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: L. Balents;O. Starykh

Hybrid Wannier Chern bands in magic angle twisted bilayer graphene and the quantized anomalous Hall effect

• DOI: 10.1103/physrevresearch.3.013242
• 发表时间: 2021-03-15
• 期刊: PHYSICAL REVIEW RESEARCH
• 影响因子: 4.2
• 作者: Hejazi, Kasra;Chen, Xiao;Balents, Leon
• 通讯作者: Balents, Leon

Realization of quantum dipoles in triangular lattice crystal Ba3Yb(BO3)3

• DOI: 10.1103/physrevb.104.l220403
• 发表时间: 2021-10
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: R. Bag;M. Ennis;Chunxiao Liu;S. Dissanayake;Zhenzhong Shi;Jue Liu;L. Balents;S. Haravifard