We expand the concept of frustration in Mott insulators and quantum spin liquids to metals with flat bands. We show that when inter-orbital hopping $t_2$ dominates over intra-orbital hopping $t_1$, in a multiband system with strong spin-orbit coupling $λ$, electronic states with a narrow bandwidth $W\sim t_2^2/λ$ are formed compared to a bandwidth of order $t_1$ for intra-orbital hopping. We demonstrate the evolution of the electronic structure, Berry phase distributions for time-reversal and inversion breaking cases, and their imprint on the optical absorption, in a tight binding model of $d$-orbital hopping on a honeycomb lattice. Going beyond quantum Hall effect and twisted bilayer graphene, we provide an alternative mechanism and a richer materials platform for achieving flat bands poised at the brink of instabilities toward novel correlated and fractionalized metallic phases.
Frustration effects on the magnetization plateau physics in a trimerized quantum spin-1/2 chain
Instituto de Física, Universidade Federal de Mato Grosso do Sul（南马托格罗索联邦大学物理研究所）；Departamento de Física, Universidade Federal de Santa Maria（圣玛丽亚联邦大学物理系）
Frustration from Localized Zhang-Rice States: A Unified Theory of Doping-Driven Magnetic Transitions in Cuprates
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院人工结构与量子控制教育部重点实验室）
A d-Electron Heavy-Fermion-Like Superconductor with Frustration-Induced Flat Bands
University of Pittsburgh（匹兹堡大学）；Weizmann Institute of Science（魏茨曼科学研究所）；Ames National Laboratory（艾姆斯国家实验室）；Iowa State University（爱荷华州立大学）；Washington University at St. Louis（圣路易斯华盛顿大学）；University of Arizona（亚利桑那大学）；Oak Ridge National Laboratory（橡树岭国家实验室）；The Pennsylvania State University（宾夕法尼亚州立大学）
Quantum criticality and emergent orders in the spin-1 bilinear-biquadratic-Kitaev chain
National Laboratory of Solid State Microstructures（固体微结构物理国家重点实验室）；Department of Physics, Nanjing University（南京大学物理学院）；Suzhou Institute for Advanced Research, University of Science and Technology of China（中国科学技术大学苏州高等研究院）；School of Artificial Intelligence and Data Science, University of Science and Technology of China（中国科学技术大学人工智能与数据科学学院）；College of Physics, Nanjing University of Aeronautics and Astronautics（南京航空航天大学物理学院）；Key Laboratory of Aerospace Information Materials and Physics (NUAA), MIIT（工业和信息化部航空航天信息材料与物理重点实验室）；Collaborative Innovation Center of Advanced Microstructures, Nanjing University（南京大学先进微结构协同创新中心）
Quantum Spin Liquid with Emergent Chiral Order in the Triangular-lattice Hubbard Model
在半填充三角格子哈伯德模型的中间相互作用区域中，自旋挫挫和电荷涨落的相互作用产生了一种奇异的量子态，而这种态的性质还存在争议.利用SU（2）$_{\rm{spin}} \otimes $ U（1）$_{\rm{charge}}$对称性实现的密度矩阵重整化群，研究了定义在直到圆周$W=6$的长圆柱几何上的三角格子哈伯德模型.一个带隙的量子自旋液体，与现场相互作用$9 \lesssim U / t \lesssim 10.75$，被确定之间的金属和反铁磁Mott绝缘相。特别是，我们发现，这种自旋液体开发了一个强大的远程自旋标量手征相关的系统长度$L$的增加，这毫不含糊地揭示了自发的时间反演对称性破缺。此外，纠缠谱的简并性支持了基态的对称性分数化和自旋边缘模。本文还讨论了这种中间自旋液体中手征序的可能起源及其与类旋光激发的关系。
Emergent dynamical Kondo coherence and competing magnetic order in a correlated kagome flat-band metal CsCr6Sb6
ShanghaiTech University（上海科技大学）；Fudan University（复旦大学）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交大李政道研究所）；Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所（北京凝聚态物理国家研究中心））；University of Chinese Academy of Sciences（中国科学院大学）；Analytical Instrumentation Center, School of Physical Science and Technology, ShanghaiTech University（上海科技大学分析测试中心）；Shanghai Research Center for Quantum Sciences（上海量子科学研究与创新中心）；ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University（上海科技大学拓扑物理实验室）
Emergent Vortex Ordering in a Multiflavor Pyrochlore-Lattice Compound GeCo$_2$O$_4$
University of Science and Technology of China（中国科学技术大学）；Comprehensive Research Organization for Science and Society (CROSS)（综合研究组织科学社会）；Rutherford Appleton Laboratory（鲁瑟福阿普顿实验室）；Peking University（北京大学）；China Institute of Atomic Energy（中国原子能科学研究院）
Emergent Chiral Spin Crystal Phase in (111) SrRuO3 Thin Films
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；School of Photoelectric Engineering, Changzhou Institute of Technology（常州工学院光电工程学院）
Dichotomy of flat bands in the van der Waals ferromagnet Fe$_5$GeTe$_2$
Rice University（莱斯大学）；University of Washington（华盛顿大学）；Oak Ridge National Laboratory（橡树岭国家实验室）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Kyung Hee University（庆熙大学）
Emergent Surface Kondo Flat Band Driven by Competing Interactions in a Topological Ferromagnet
Max Planck Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）；Leibniz Institute for Solid State and Materials Research, IFW Dresden（德累斯顿IFW莱布尼茨固态与材料研究所）；Donostia International Physics Center（圣塞巴斯蒂安国际物理中心）；Luxembourg Institute of Science and Technology (LIST)（卢森堡科学与技术研究所）；Technische Universität Dresden（德累斯顿工业大学）；Helmholtz-Zentrum Berlin für Materialien und Energie（柏林亥姆霍兹材料与能源中心）
Emergent flat-band physics in $d^{9-δ}$ multilayer nickelates
最近的实验表明，形式为RE $_{p+1}$ Ni $_p$ O $_{2p+2}$的还原多层稀土（RE）镍氧化物可能属于超导镧系镍酸盐的新家族。本文采用改进的真实多体框架研究了Pr $_{4}$ Ni $_3$ O $_{8}$和Nd $_{6}$ Ni $_5$ O $_{12}$的相关电子结构。结果表明，Ni- $d_{x^2-y^2}$和Ni- $d_{z^2}$自由度的相互作用决定了这两个体系的低能物理性质.虽然Ni- $d_{x^2-y^2}$轨道总是在（轨道选择性）Mott绝缘区域附近高度相关，但Ni- $d_{z^2}$轨道产生有趣的非色散特征。在低温下，Pr化合物在费米能级上仍表现出类似量子点的Ni- $d_{x^2-y^2}$衍生态，但Nd化合物的相互作用费米能级被Ni- $d_{z^2}$控制的平带所掩盖.这些发现很好地转化为以前的表征掺杂的无限层镍酸盐，因此进一步使一种非常规的超导机制的情况下，这是从一个不同的高- $T_{\rm c}$铜酸盐。
Frustration-driven topological textures on the honeycomb lattice: antiferromagnetic meron-antimeron and skyrmion crystals emerging from spiral spin liquids
