发表机构
Brock University; Indian Institute of Technology Madras（布鲁克大学; 印度马德拉斯理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究揭示隐藏对称性，证明所有密堆积晶格在最近邻和次近邻耦合下等价，并构建统一相图，为阻挫磁体研究提供新视角。
AI 中文摘要
面心立方（fcc）晶格上的海森堡反铁磁体是阻挫的典型例子。fcc晶格只是无穷多种密堆积结构中的一种，所有这些结构都具有相同的引起阻挫的局域几何。在本快报中，我们展示了一种隐藏对称性，它将所有密堆积晶格上的经典磁体联系起来。这种对称性源于紧束缚模型中的类似性质，该性质可能解释锂和钠金属的无序低温结构。在磁体中，当耦合仅限于最近邻（$J_1$）和次近邻（$J_2$）时，该对称性成立。它保证了在Luttinger-Tisza层面上所有密堆积晶格是等价的。对于任意给定的$J_1$和$J_2$值，它们具有相同的基态能量。它们的基态动量在投影到堆叠平面时是相同的。我们构建了一个统一的相图，作为$J_1$和$J_2$耦合的函数，适用于任何密堆积晶格上的海森堡、XY和Ising磁体。在每个相中，所有密堆积晶格上的基态简并度相同，即使考虑了多Q螺旋。该相图可以轻松适用于任何由具有类似耦合的堆叠三角层组成的磁体。经典基态之上的涨落不受任何对称性关联。这表明密堆积结构可以在序-by-无序选择中显示出有趣的差异。
英文摘要
The Heisenberg antiferromagnet on the fcc lattice is a canonical example of frustration. The fcc lattice is but one of an infinite number of close-packed structures, all of which have the same frustration-inducing local geometry. In this letter, we demonstrate a hidden symmetry that relates classical magnets on all close-packed lattices. This symmetry derives from a similar property in tight binding models that may explain the disordered low-temperature structures of lithium and sodium metals. In magnets, the symmetry holds when couplings are restricted to nearest ($J_1$) and next-nearest neighbours ($J_2$). It guarantees that all close-packed lattices are equivalent at the Luttinger-Tisza level. For any given values of $J_1$ and $J_2$, they have the same ground-state energy. Their ground state momenta are identical when projected onto the stacking plane. We construct a unified phase diagram as a function of $J_1$ and $J_2$ couplings for Heisenberg, XY and Ising magnets on any close-packed lattice. In each phase, the ground-state degeneracy is the same on all close-packed lattices, even after accounting for multi-Q spirals. This phase diagram can be easily adapted to any magnet composed of stacked triangular layers with similar couplings. Fluctuations above the classical ground state(s) are not related by any symmetry. This suggests that close-packed structures can show interesting differences in order-by-disorder selection.
