实现手性自旋液体的一个有前景的途径是通过量子涨落对经典非共面自旋态进行量子熔化。在经典领域中，这类非共面序可以通过超越最近邻的相互作用被有效稳定。受近期具有枫叶晶格几何结构的材料合成的启发，我们研究了交叉方块耦合对该几何结构下基本海森堡反铁磁体（以及其铁磁对应体系）的影响。利用大规模蒙特卡洛模拟并结合半解析分析，我们发现了一个丰富的非共面态谱，包括一种新颖的二十面体序以及非公度自旋螺旋。为了考察这些态的潜在量子熔化，我们使用赝费米子泛函重整化群（pf-FRG）模拟分析了这些模型的量子 S = 1/2 变体。值得注意的是，我们确实发现了缺乏长程磁序的扩展参数区域——位于经典上由非共面序占据的区域中——我们推测这些区域可能与手性量子自旋液体的可能形成有关。
英文摘要：
A promising route towards the realization of chiral spin liquids is the quantum melting of classically noncoplanar spin states via quantum fluctuations. In the classical realm, such noncoplanar orders can effectively be stabilized by interactions beyond nearest neighbors. Motivated by the recent synthesis of materials with a maple-leaf lattice geometry, we study the effect of cross-plaquette couplings on elementary Heisenberg antiferromagnets for this geometry (as well as their ferromagnetic counterparts). We find a rich spectrum of noncoplanar states, including a novel icosahedral order as well as incommensurate spin spirals, using large-scale Monte Carlo simulations in combination with a semi-analytical analysis. To inspect the potential quantum melting of these states, we analyze the quantum $S = 1/2$ variant of these models using pseudo-fermion functional renormalization group (pf-FRG) simulations. Notably, we indeed find extended parameter regimes lacking long-range magnetic order -- in regions classically occupied by noncoplanar orders -- which we putatively identify with the possible formation of chiral quantum spin liquids.
An extended non-magnetic phase in the spin-1/2 Heisenberg antiferromagnet from the ruby to the maple-leaf lattice
Freie Universität Berlin（柏林自由大学）；University of Cologne（科隆大学）；Helmholtz-Zentrum Berlin für Materialien und Energie（柏林亥姆霍兹材料与能源中心）；Indian Institute of Technology Madras（马德拉斯印度理工学院）
Thermodynamics of the Heisenberg antiferromagnet on the maple-leaf lattice
Helmholtz-Zentrum Berlin für Materialien und Energie（亥姆霍兹柏林材料能源中心）；Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin（达勒姆复杂量子系统中心与柏林自由大学物理系）；Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；Institute of Physics, University of Bonn（波恩大学物理研究所）
Exact quantum spin liquids with topological order on maple-leaf and trellis lattices
Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；T.C.M. Group, Cavendish Laboratory, University of Cambridge（剑桥大学卡文迪许实验室 T.C.M. 组）
Spin excitation of the Heisenberg antiferromagnet with frustration: from the bounce-lattice antiferromagnet through the maple-leaf-lattice antiferromagnet to the exact-dimer system
Graduate School of Science, University of Hyogo（兵库大学理学研究科）；National Institute for Quantum Science and Technology (QST) SPring-8（量子科学技术研究开发机构SPring-8）
