发表机构
Okinawa Institute of Science and Technology Graduate University; Institute for Solid State Physics, University of Tokyo; Research Institute for Synchrotron Radiation Science (HiSOR), Hiroshima University; Japan Synchrotron Radiation Research Institute; Clarendon Laboratory, University of Oxford; Department of Physics, Faculty of Science, Hokkaido University; Department of Applied Chemistry, Faculty of Science Division 1, Tokyo University of Science（冲绳科学技术大学院大学; 东京大学固体物理研究所; 广岛大学同步辐射科学研究机构; 日本同步辐射研究机构; 牛津大学克拉伦登实验室; 北海道大学理学部物理学科; 东京理科大学第一理学部应用化学科）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出利用半导体能带极值作为构建块，在二维半导体GdGaI中发现手性三重-q反铁磁态，产生显著自发反常霍尔效应，为设计手性量子物质提供了简单概念。
AI 中文摘要
理解手性量子相涌现的规律是一项基础性挑战，不仅有助于揭示量子态形成的新机制，而且对于实现由手性和拓扑产生的巨大电子响应及输运现象也至关重要。虽然金属中的费米面不稳定性可以通过多个竞争散射通道稳定复杂的有序态，但其微观起源往往被底层电子结构的复杂性所掩盖，限制了通用微观设计原理的发展。在此，我们提出一种基于半导体能带极值简单性的互补策略。利用层状范德华半导体GdGaI（其低能电子结构由简单的电子和空穴谷组成），我们发现了交织的手性三重-q反铁磁态的自发涌现，并伴随电子-空穴带边的协同重构，这超出了对单-q基态的常规预期。这种集体重构产生了显著的动量空间贝里曲率，尽管材料具有半导体特性且净磁化可忽略，仍导致了显著的自发反常霍尔效应。值得注意的是，这种手性态在原子级明确定义（约2a）、拓扑非平凡的磁织构中实现，表明此类集体量子态可以在极小的长度尺度上从简单的二维磁性半导体中涌现。更广泛地说，我们的结果引入了一个极其简单的设计概念：利用简单半导体能带极值作为动量空间中类共振相互作用的构建块，为贝里曲率、拓扑输运和涌现量子相提供了一条途径。
英文摘要
Understanding the principles governing the emergence of chiral quantum phases is a fundamental challenge, not only for uncovering new mechanisms of quantum-state formation but also for realizing giant electronic responses and transport phenomena arising from chirality and topology. While Fermi-surface instabilities in metals can stabilize complex ordered states through multiple competing scattering channels, their microscopic origin is often obscured by the complexity of the underlying electronic structure, limiting the development of general microscopic design principles. Here, we introduce a complementary strategy based on the simplicity of semiconductor band extrema. Using the layered van der Waals semiconductor GdGaI, whose low-energy electronic structure consists of simple electron and hole valleys, we discover the spontaneous emergence of an intertwined chiral triple-$q$ antiferromagnetic state accompanied by a cooperative reconstruction of the electron-hole band edges, beyond the conventional expectation of a single-$q$ ground state. This collective reconstruction generates substantial momentum-space Berry curvature, giving rise to a pronounced spontaneous anomalous Hall effect despite the semiconducting character and negligible net magnetization. Remarkably, this chiral state is realized within an atomically well-defined ($\approx2a$), topologically nontrivial magnetic texture, showing that such collective quantum states can emerge at an exceptionally small length scale from a simple two-dimensional magnetic semiconductor. More broadly, our results introduce a remarkably simple design concept for chiral quantum matter: using simple semiconductor band extrema as building blocks for resonance-like interplay in momentum space, providing a route to Berry curvature, topological transport, and emergent quantum phases.
Comments22 pages, 4 figures
