NSF-BSF: Theory of Quantum Materials

NSF-BSF：量子材料理论

• 批准号: 2310312
• 负责人: Steven Kivelson
• 金额: $ 65万
• 依托单位: Stanford University
• 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: 2023-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2310312&HistoricalAwards=false
• 关键词: NSF; BSF; Theory; Quantum; Materials

NONTECHNICAL SUMMARYThis award supports theoretical research on atomic scale models of interacting electrons and ions in so-called "quantum materials". Some examples of quantum materials include high-temperature superconductors, two layers of carbon atom sheets on top of each other with a relative twist angle, and materials in which the electron-electron interaction energies are comparable or much larger compared to their kinetic energies. A major focus of this project is to unravel the mysterious properties of superconductors through which electrons flow in unison without losing any of their energy below a certain critical temperature. While quantum mechanics has allowed scientists to understand and predict most properties of "conventional" superconductors, achieving a fundamental understanding of unconventional superconductors, which include high-temperature superconductors and twisted layers of carbon atoms, has remained elusive. In this project, the PI and his team will study an array of atomic scale models on material systems and topics, including unconventional superconductors, that are at the heart of contemporary condensed matter physics.The quantum many-body problem that is the topic of this project has diverse and deep connections to other fields of physics, from string theory to quantum information. In addition, quantum materials have had a tremendous impact on both fundamental science and technology, and hence, an increased understanding of the problems to be investigated in this project has the potential to influence broader developments in science and technology. This award will also contribute to the development of the scientific workforce, as it will support the research training of graduate students and postdocs, who are likely to take leading positions in academia and industry in the future.TECHNICAL SUMMARYThis award supports theoretical research on microscopic models of interacting electrons and phonons in quantum materials. Particular attention will be paid to the intermediate coupling regime, where interactions and kinetic terms are of comparable magnitude. Interactions are generally minimized when the constituent particles form suitable real-space structures, such as a Wigner crystal, while kinetic terms are diagonal in momentum space. Hence, the intermediate coupling regime is where quantum frustration is maximal. The PI will also apply a Landau-Ginzburg-Wilson effective field theoretical approach to study problems in which multiple distinct ordering tendencies are present, and the effective frustration reflects the competition between them. Specific problems of this general sort that will be the focus of study are (i) Solvable models of unconventional metallic regimes, particularly focusing on lessons for cuprate superconductors, (ii) Phenomenological and microscopic theories of systems with multiple intertwined ordering tendencies, including multiple possible uniform superconducting orders, pair-density-wave order, charge and spin density wave order, and electron nematic order, (iii) Correlated phases of multi-valley two-dimensional electron gases, and (iv) Generalizing the classification of distinct phases, especially unconventional superconducting phases, to quasi-periodic systems including Moiré materials in which Bloch's theorem does not apply and conventional symmetry classifications at the very least must be reconsidered.The quantum many-body problem that is the topic of this project has diverse and deep connections to other fields of physics, from string theory to quantum information. In addition, quantum materials have had a tremendous impact on both fundamental science and technology, and hence, an increased understanding of the problems to be investigated in this project has the potential to influence broader developments in science and technology. This award will also contribute to the development of the scientific workforce, as it will support the research training of graduate students and postdocs, who are likely to take leading positions in academia and industry in the future.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所谓的“量子材料”中相互作用电子和离子的原子量表模型的理论研究。量子材料的一些示例包括高温超导体，两层碳原子片彼此之间具有相对扭曲的角度，以及与它们的动能相比，电子 - 电子相互作用能量相当或更大的材料。该项目的主要重点是揭开超导体的神秘特性，电子通过该特性逐渐流动，而不会在某个临界温度以下失去任何能量。虽然量子力学允许科学家理解和预测“常规”超导体的大多数特性，从而获得了对非常规超导体的基本理解，其中包括高温超导体和碳原子的扭曲层，但仍然难以捉摸。在这个项目中，PI和他的团队将研究有关材料系统和主题的一系列原子量表模型，包括非常规的超导体，这些模型是当代凝聚态物理物理学的核心。从字符串理论到量子理论的其他领域，该项目的量子多体性问题是该项目的量子多体性问题。此外，量子材料对基本科学和技术都产生了巨大影响，因此，对该项目中要研究的问题的越来越多，有可能影响科学和技术方面的更广泛发展。该奖项还将为科学劳动力的发展做出贡献，因为它将支持研究生和博士后的研究培训，他们将来可能会在学术界和工业中担任领先地位。技术摘要奖支持对量化电子和量子材料中互动电子学和声音的微观模型的理论研究。特别关注中间耦合方案，相互作用和动力学术语具有可比性。当构造粒子形成合适的真实空间结构（例如wigner晶体）时，相互作用通常会最小化，而动力学术语在动量空间中是对角线的。因此，中间耦合方案是量子挫败感最大的地方。 PI还将采用Landau-Ginzburg-Wilson有效的领域理论方法来研究存在多种不同有序趋势的问题，并且有效的挫败感反映了它们之间的竞争。 Specific problems of this general sort that will be the focus of study are (i) Solvable models of unconventional metallic regimes, particularly focusing on lessons for cuprate superconductors, (ii) Phenomegenological and microscopic theories of systems with multiple intertwined ordering tendencies, including multiple possible uniform superconductors orders, pair-density-wave order, charge and spin density wave order, and electron nematic order, (iii)多阀多二维电子气体的相关阶段，以及（iv）将不同阶段的分类，尤其是非常规的超导阶段的分类到准时的材料，包括moiré材料，包括bloch的定理，其中最少要对此进行了质量的质量，这些问题是多样化的。物理领域，从字符串理论到量子信息。此外，量子材料对基本科学和技术都产生了巨大影响，因此，对该项目中要研究的问题的越来越多，有可能影响科学和技术方面的更广泛发展。该奖项还将为科学劳动力的发展做出贡献，因为它将支持研究生和博士后的研究培训，他们将来可能会在学术界和行业中担任领先地位。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子的智力和更广泛的影响来评估的支持，并被认为是珍贵的支持。