Dynamics and Quantum Phase Transitions of Chiral Fermi Liquids

非技术性总结该奖项支持理论研究和教育，重点是理解和描述材料中电子的相关运动，因为它们相互作用，以及排列在晶格上的底层原子核。其中一个关键因素是电子自旋。从量子力学的角度来看，电子的行为就像一个非常小的陀螺，而且由于它的电荷，它也像一个微小的磁铁。当电子在晶格中移动时，原子核的电场看起来像一个磁场，它与电子的磁性相互作用，因此，它的自旋方向。在这个研究项目中，PI将开发一个理论描述的电子，相互之间强烈相互作用，并通过其在自然和人工构造的晶体材料中的自旋与原子核的周期性晶格。PI将研究电子与晶格相互作用和电子相互作用之间的相互作用所产生的现象;这导致了一种新型的自旋波，可能用于在计算设备中携带数据。这些自旋波可以在几乎没有能量损失的情况下在宏观距离上提供自旋信息的传输，并允许实现新的计算概念。 在研究方面，PI将为多学院课程“凝聚态物理学高级主题”开发一个新的迷你课程，并组织一个关于量子相变的国际研讨会。通过Funsize Physics网站和公开讲座，将研究成果的重要性传达给更广泛的受众。技术概要该奖项支持理论研究和教育，以发展和追求电子之间以及自旋和轨道自由度之间具有强相关性的材料系统的一致性理论的后果，手性费米液体理论。PI将探索这个理论的预测与实验结果。该研究涉及在具有强自旋轨道耦合的材料中识别和调查电子物质的可能新相，以及分析自旋轨道耦合和电子-电子相互作用之间相互作用的各种实验指纹。该项目的主要目标包括：i）手性费米液体中电子和电子偶极自旋共振效应的理论; ii）手性费米液体中集体自旋激发的拉曼散射的多体理论; iii）最近在三维拓扑绝缘体表面观察到的手性自旋波和手性激子的理论分析（硒化铋）; iv）具有SOC的二维电子系统的可能的不稳定相的分析;以及v）非手性费米液体的自旋通道中的可能的不稳定性之间的竞争的分析。在研究方面，PI将为多学院课程“凝聚态物理学高级主题”开发与该奖项相关的主题的新迷你课程，并将组织一个关于量子相变的国际研讨会。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis award supports theoretical research and education that focuses on understanding and describing the correlated motion of electrons in materials as they interact with each other and the underlying atomic nuclei arranged on a crystalline lattice. A key ingredient is the electron spin. Quantum mechanically, the electron behaves like a very tiny top, and because of its charge like a tiny magnet as well. As the electron moves through the crystalline lattice, the electric field of the nuclei looks like a magnetic field which interacts with the magnetic character of the electron and so, the direction of its spin. In this research project, the PI will develop a theoretical description of electrons that interact strongly with each other and with the periodic lattice of nuclei through its spin in natural and artificially constructed crystalline materials. The PI will investigate a phenomenon which results from the interplay between the electrons interacting with the lattice and electrons interacting with each other; this leads to a new type of spin wave which might be used to carry data in computing devices. These spin waves can provide transfer of spin information over macroscopic distances with virtually no loss of energy, and allow for the implementation of new computing concepts. In connection with the research, the PI will develop a new mini-course on subjects relevant to this award for a multi-faculty course "Advanced Topics in Condensed Matter Physics" and organize an international workshop on quantum phase transitions. The significance of the research results will be communicated to a broader audience through the Funsize Physics website and public lectures.TECHNICAL SUMMARYThis award supports theoretical research and education to develop and pursue the consequences of a consistent theory of materials systems with strong correlations among electrons and among spin and orbital degrees of freedom, a chiral Fermi liquid theory. The PI will explore predictions of this theory with consequences accessible to experiment. The research involves the identification and investigation of possible new phases of electronic matter in materials with strong spin-orbit-coupling and analyses of various experimental fingerprints of the interplay between spin-orbit coupling and electron-electron interaction. The main thrusts of the project include developing: i) a theory of electron-and electron-dipole spin resonance effects in a chiral Fermi liquid; ii) a many-body theory of Raman scattering from collective spin excitations in a chiral Fermi liquid; iii) a theoretical analysis of recently observed chiral spin waves and chiral excitons at the surface of a three-dimensional topological insulator (bismuth selenide); iv) an analysis of possible nematic phases of a two-dimensional electron system with SOC; and v) an analysis of the competition among possible instabilities in the spin channel of a non-chiral Fermi liquid. In connection to the research, the PI will develop new mini-courses on subjects relevant to this award for a multi-faculty course "Advanced Topics in Condensed Matter Physics" and will organize an international workshop on quantum phase transitions. The significance of the research results will be communicated to a broader audience through the Funsize Physics website and public lectures.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.