发表机构
ETH Zurich; PSI Center for Neutron and Muon Sciences; Institut Néel, CNRS UPR2940; School of Physics, University of Bristol; PSI Center for Scientific Computing, Theory and Data（苏黎世联邦理工学院; 保罗谢尔研究所中子与μ子科学中心; 内勒研究所，法国国家科学研究中心; 布里斯托大学物理学院; 保罗谢尔研究所科学计算、理论与数据中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究构建基于帽形 tiling 的爱因斯坦人工自旋冰模型，揭示其两阶段部分有序过程，确立其为理解准晶磁性的蓝图，可设计周期系统无等效的非常规磁相。
AI 中文摘要
天然存在的块状准晶体十分稀有，磁性准晶体更为罕见，化学约束通常只允许合成近似物而非真正的准晶磁体。本文介绍一种基于新近发现的爱因斯坦晶格（Hat tiling，即帽形 tiling）的人工自旋冰，该结构由首个已知仅能非周期铺满平面的形状——帽形（hat）构成。爱因斯坦人工自旋冰具有无平移对称性的长程结构序，以及具有明确定义的局域基态和激发态的低连接度顶点。这些特性共同构成了二维准晶磁体的模型，我们通过磁力显微镜和并行 tempering 蒙特卡洛模拟对其磁关联进行探测。我们识别出由磁激发的两种可能位置之间的竞争驱动的两阶段部分有序过程，该竞争在基态流形中得到解决：每个反帽形（antihat）上恰好有一个磁激发被囚禁，且该流形仍保持宏观简并。这产生了一种特殊的中程有序，其中潜在的准周期长程序受到严格约束的无序的随机调制。我们的发现确立了爱因斯坦人工自旋冰作为理解准晶磁性的蓝图，证明了准周期单调片几何可被用于设计周期系统中无直接等效物的非常规磁相。
英文摘要
Naturally occurring bulk quasicrystals are rare, and magnetic instances are rarer still, with chemical constraints typically permitting the synthesis of approximants rather than true quasicrystalline magnets. Here, we present an artificial spin ice based on a recently discovered Einstein lattice, the Hat tiling, which is built from the first known shape - the hat - that tiles the plane only aperiodically. The Einstein artificial spin ice has long-range structural order with no translational symmetry, and low-connectivity vertices with well-defined local ground states and excitations. Together, these properties provide a model two-dimensional quasicrystalline magnet, with magnetic correlations that we probe with magnetic force microscopy and parallel-tempered Monte Carlo simulations. We identify a two-stage partial ordering process, driven by the competition between two possible positions for magnetic excitations. This competition is resolved in the ground-state manifold, where exactly one magnetic excitation is caged on each antihat, yet the manifold remains macroscopically degenerate. This yields an unusual type of medium-range order, where the underlying quasiperiodic long-range order is randomly modulated by a strictly constrained disorder. Our findings establish the Einstein artificial spin ice as a blueprint for understanding quasicrystalline magnetism, demonstrating how quasiperiodic monotile geometries can be exploited to engineer unconventional magnetic phases with no direct equivalent in periodic systems.
CommentsMain text 8 pages and 4 figures, Methods 3 pages, Supplementary material 10 pages
