Transport and Superconductivity in Strongly Correlated Quantum Matter

强相关量子物质中的输运和超导

• 批准号: 2111379
• 负责人: Philip Phillips
• 金额: $ 37.5万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2111379&HistoricalAwards=false
• 关键词: Transport; Superconductivity; Strongly; Correlated; Quantum

NONTECHNICAL SUMMARYThis award supports theoretical research aimed at understanding electronic and transport properties of systems in which strong interactions between electrons lead to emergent behavior such as high temperature superconductivity. In a superconductor, electrons conduct electricity without any loss, but this typically happens only at low temperatures. As electrical loss represents a significant portion of all electrical bills, a room temperature superconductor would represent a major advance in power transmission. The PI's work is focused on understanding a class of high-temperature superconductors discovered in 1987 that have defied understanding within the so-called BCS theory proposed in 1957 by Bardeen, Cooper, and Schrieffer. The primary difficulty is that while the BCS theory works fine for metals such aluminum where the interaction between the electrons can be ignored, this is not the case for the high-temperature superconductors where superconductivity occurs by doping materials which are insulators due to strong repulsion between electrons. The PI has advanced an exactly solvable model for such systems and shown how superconductivity emerges. Since the model is exactly solvable, a clear picture emerges as to how the BCS theory must be modified. The PI will work to quantify the differences and construct the universal features of superconductivity in these materials that have defied description in terms of the standard BCS theory.This award also supports training of graduate students seeking their PhD degrees in theoretical physics. The PI will be involved with other educational and outreach activities, such as continuing to revise his graduate textbook in theoretical solid state physics, serving on the Editorial Boards of prominent scientific journals, advancing initiatives within the American Physical Society at the intersection of physics and race, and working to increase diversity in the scientific workforce.TECHNICAL SUMMARYThis award supports theoretical research focused on new methods for the transport and superconducting properties of strongly correlated electron systems by using exactly solvable models, numerical calculations, and renormalization techniques to establish the existence of strongly coupled fixed points. The exactly solvable models allow new insight into the 35-year old problem of superconductivity in doped Mott insulators such as the high-temperature superconductors. The goal is to ascertain what new features emerge from Mott physics in the superconducting state. Another goal of the exactly solvable models is to determine if the physics they embody is governed by a new strongly coupled fixed point in much the same way Fermi liquid theory dictates the physics of simple metals. Success here could provide an organizing principle in the physics of strongly correlated electron matter. Finally, the focus on numerical calculations to determine the phase diagram of the dilute electron gas in the presence of a periodic potential is aimed at informing new experiments that have revealed novel insulating states that break translational symmetry in Moire bilayer systems.This award also supports training of graduate students seeking their PhD degrees in theoretical physics. The PI will be involved with other educational and outreach activities, such as continuing to revise his graduate textbook in theoretical solid state physics, serving on the Editorial Boards of prominent scientific journals, advancing initiatives within the American Physical Society at the intersection of physics and race, and working to increase diversity in the scientific workforce.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理论研究，旨在了解系统的电子和传输特性，在这些系统中，电子之间的强烈相互作用会导致诸如高温超导性等新兴行为。在超导体中，电子在没有任何损失的情况下进行电力，但这通常仅在低温下发生。由于电气损耗代表了所有电费的很大一部分，因此室温超导体将代表电力传输的重大进步。 PI的工作重点是理解1987年发现的一类高温超导体，这些导体在1957年由Bardeen，Cooper和Schrieffer于1957年提出的所谓的BCS理论中不理解。 主要的困难是，尽管BCS理论在金属中效果很好，例如铝可以忽略电子之间的相互作用，但对于高温超导体而言，事实并非如此，在这些高温超导体中，由于电子之间的强阻止，掺杂材料是绝缘体的掺杂材料而发生的。 PI为此类系统提出了一个准确的可解决模型，并显示了超导性的出现。由于该模型是可以解决的，因此出现了关于必须如何修改BCS理论的清晰图片。 PI将努力量化这些材料中超导性的差异并构建超导性的普遍特征，这些材料违反了标准BCS理论的描述。该奖项还支持对寻求理论物理学博士学位的研究生的培训。 PI将参与其他教育和宣传活动，例如继续修改其理论固态物理学的研究生教科书，在著名的科学期刊的编辑委员会上工作，在美国物理社会内的倡议中推进了物理与种族的交叉点，并在科学研究中努力提高了对科学研究的多样性的努力。通过使用可溶解的模型，数值计算和重新规定技术来确定存在强耦合的固定点的存在，从而强烈相关的电子系统的超导性能。可解决的模型允许对掺杂的Mott绝缘子（例如高温超导体）中35岁的超导性问题进行新的见解。 目的是确定超导状态下Mott物理学的新功能。 确切可解决的模型的另一个目标是确定它们体现的物理学是否由新的强耦合固定点控制，就像费米液体理论决定了简单金属的物理学一样。 这里的成功可以提供强度相关的电子物质物理学的组织原理。 最后，关注数值计算以确定在存在周期电位的情况下稀释电子气体的相图，旨在告知新实验，这些实验揭示了新的绝缘状态，即在Moire Biyer System中破坏翻译对称性。该奖项还支持研究研究生的研究生培训，以寻求理论上的PHD学位。 PI将参与其他教育和宣传活动，例如继续修改其理论固态物理学的研究生教科书，在著名的科学期刊的编辑委员会上工作，在美国物理社会内部的举措中推进了物理和种族的交集，并通过评估授权的多样性来提高诺斯夫的多样性。基金会的智力优点和更广泛的影响评论标准。

项目成果

Thermodynamics of an exactly solvable model for superconductivity in a doped Mott insulator

掺杂莫特绝缘体中超导精确可解模型的热力学

• DOI: 10.1103/physrevb.105.184509
• 发表时间: 2022
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Zhao, Jinchao;Yeo, Luke;Huang, Edwin W.;Phillips, Philip W.
• 通讯作者: Phillips, Philip W.

Kitaev chain with a fractional twist

• DOI: 10.1103/physrevb.106.125109
• 发表时间: 2022-04
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Bora Basa;Gabriele La Nave;P. Phillips

Topological Mott insulator at quarter filling in the interacting Haldane model

• DOI: 10.1103/physrevresearch.5.013162
• 发表时间: 2022-07
• 期刊: Physical Review Research
• 影响因子: 4.2
• 作者: P. Mai;B. Feldman;P. Phillips

Correlated Hofstadter spectrum and flavour phase diagram in magic-angle twisted bilayer graphene

• DOI: 10.1038/s41567-022-01589-w
• 发表时间: 2021-07
• 期刊: Nature Physics
• 影响因子: 19.6
• 作者: Jiachen Yu;B. Foutty;Zhaoyu Han;M. Barber;Y. Schattner;Kenji Watanabe;T. Taniguchi;P. Phillips;Zhixuan Shen;S. Kivelson;B. Feldman

Probing the bulk plasmon continuum of layered materials through electron energy loss spectroscopy in a reflection geometry

• DOI: 10.1103/physrevb.106.155152
• 发表时间: 2022-03
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: C. Boyd;L. Yeo;P. Phillips