相互作用范围对磁性 hedgehog 晶格相图的影响
Effect of interaction range on the phase diagram of magnetic hedgehog lattices
- The University of Tokyo（东京大学）
- RIKEN Center for Emergent Matter Science (CEMS)（理化学研究所 涌现物质科学中心）
- Hiroshima University（广岛大学）
- University of Fukui（福井大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过蒙特卡洛模拟系统改变交换相互作用范围，发现中等范围相互作用最有利于稳定磁性 hedgehog 晶格，并揭示了两种不同类型的 3Q-HL 及其稳定性对相互作用范围的依赖，为统一理解相图提供了框架。
AI中文摘要：
拓扑自旋纹理因其涌现的电磁性质（包括拓扑霍尔效应和拓扑能斯特效应）而引起了广泛关注。其中，磁性 hedgehog 晶格（HLs）是三维拓扑自旋纹理，承载着涌现的磁单极子和反磁单极子。HLs 已在金属化合物中被识别，例如 $\mathrm{MnSi}_{1-x}\mathrm{Ge}_x$ 和 $\mathrm{SrFeO_3}$。已有多种理论模型被提出，这些模型包含短程或长程相互作用，通常分别被视为绝缘系统和金属系统的有效描述。然而，相互作用范围在稳定 HLs 中的作用仍仅被部分理解。为解决这一空白，我们通过系统改变交换相互作用的范围和空间衰减来研究 HLs 的稳定性，从而在通常与局域自旋绝缘模型和巡游电子金属模型相关的相互作用分布之间进行插值。基于广泛的蒙特卡洛模拟，我们发现 HLs 在广泛的相互作用范围内是稳定的。有趣的是，在所考察的相互作用分布中，中等范围的相互作用特别有利于稳定 HLs。它们产生了两种不同类型的 $3Q$-HLs，这两种类型在每磁晶胞中单极子-反单极子对的数量上有所不同，且它们的相对稳定性敏感地依赖于相互作用范围。我们的结果为从微观相互作用模型调节相图提供了一个统一框架，为解释候选材料中的实验提供了指导。
英文摘要：
Topological spin textures have attracted considerable attention through their emergent electromagnetic properties, including the topological Hall effect and the topological Nernst effect. Among them, magnetic hedgehog lattices (HLs) are three-dimensional topological spin textures that host emergent magnetic monopoles and antimonopoles. HLs have been identified in metallic compounds, such as $\mathrm{MnSi}_{1-x}\mathrm{Ge}_x$ and $\mathrm{SrFeO_3}$. Various theoretical models have been proposed, with either short-range or long-range interactions, which are typically regarded as effective descriptions of insulating and metallic systems, respectively. However, the role of the interaction range in stabilizing the HLs remains only partially understood. To address this gap, we investigate the stability of HLs by systematically varying the range and spatial decay of the exchange interactions, thereby interpolating between interaction profiles commonly associated with localized-spin insulating models and itinerant-electron metallic models. Based on extensive Monte Carlo simulations, we find that HLs are stabilized over a broad interaction range. Intriguingly, among the interaction profiles examined, intermediate-range interactions are particularly favorable for stabilizing HLs. They give rise to two distinct types of $3Q$-HLs that differ in the number of monopole-antimonopole pairs per magnetic unit cell, and their relative stability depends sensitively on the interaction range. Our results provide a unified framework for tuning phase diagrams from microscopic interaction models, serving as a guideline for interpreting experiments in candidate materials.
