Dynamics and Quantum Phase Transitions of Chiral Fermi Liquids

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，因为它们彼此相互作用以及排列在晶格上的底层原子核。一个关键因素是电子自旋。量子力学上，电子表现得像一个非常小的陀螺，由于它的电荷也像一个小磁铁。当电子在晶格中移动时，原子核的电场看起来就像一个磁场，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将通过自然和人工构建的晶体材料中的自旋，对电子之间以及与原子核的周期性晶格之间的强烈相互作用进行理论描述。PI将研究由电子与晶格相互作用和电子相互作用之间的相互作用产生的现象；这就产生了一种新型的自旋波，可用于在计算设备中传输数据。这些自旋波可以在宏观距离上提供自旋信息的传递，几乎没有能量损失，并且允许实现新的计算概念。与这项研究相关，PI将为一个多学院课程“凝聚态物理高级主题”开发一个与该奖项相关的新迷你课程，并组织一个关于量子相变的国际研讨会。研究结果的意义将通过Funsize Physics网站和公开讲座传达给更广泛的受众。该奖项支持理论研究和教育，以发展和追求具有电子，自旋和轨道自由度之间强相关性的材料系统的一致理论的结果，即手性费米液体理论。PI将探索这一理论的预测和实验结果。该研究包括识别和研究具有强自旋-轨道耦合的材料中可能存在的电子物质的新相，以及分析自旋-轨道耦合与电子-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)建立手性费米液体中电子-和电子-偶极子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)三维拓扑绝缘体（硒化铋）表面最近观测到的手性自旋波和手性激子的理论分析；iv)具有SOC的二维电子系统可能的向列相分析；v)分析了非手性费米液体自旋通道中可能的不稳定性之间的竞争。与这项研究相关，PI将为一个多学院课程“凝聚态物理高级主题”开发与该奖项相关的新迷你课程，并将组织一个关于量子相变的国际研讨会。研究结果的意义将通过Funsize Physics网站和公开讲座传达给更广泛的受众。该奖项反映了美国国家科学基金会的法定使命，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.