发表机构
The University of Tokyo（东京大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在典型交替磁体CrSb中观测到g波交替磁多极子，结合多种表征技术揭示其有序特征，建立了交替磁性的微观模型及量子材料多极子有序的通用探测方法。
AI 中文摘要
在过去几年中，交替磁体（altermagnets）作为一类新型共线磁体出现，其具有破缺的时间反演对称性，为超越传统磁体的自旋电子学提供了新机遇。与铁磁体源于净磁化不同，交替磁体的非常规时间反演对称性破缺源于与高阶多极子锁定的反铁磁性磁偶极子。本文报道了在典型交替磁体CrSb中对g波交替磁多极子的直接可视化。结合高能同步辐射X射线衍射与价电子密度（VED）分析，我们揭示了Cr亚晶格间交替的VED分布存在显著的各向异性，这为g波交替磁体中预测的电十六极子反铁磁性有序提供了证据。通过极化中子衍射探测，其与反铁磁性磁偶极子的共存诱导了铁磁性磁多极子。我们进一步确定了一种交替磁性的微观模型，该模型直接关联了g波多极子与g波自旋分裂。通过对多极子的直接观测与量化，本研究为交替磁性提供了实空间指纹，并建立了量子材料中隐藏多极子有序的通用探测方法。
英文摘要
Over the past few years, altermagnets have emerged as a new class of collinear magnets with broken time-reversal symmetry, offering novel opportunities for spintronics beyond conventional magnets. Rather than from net magnetization, as in ferromagnets, the unconventional time-reversal symmetry breaking of altermagnets originates from antiferroic magnetic dipoles locked to higher-order multipoles. Here we report the direct visualization of a $g$-wave altermagnetic multipole in the canonical altermagnet CrSb. Combining high-energy synchrotron X-ray diffraction with valence electron density (VED) analysis, we uncover a pronounced directional anisotropy of the VED distribution alternating between Cr sublattices. This evidences the antiferroic order of electric hexadecapoles predicted in $g$-wave altermagnets. Its coexistence with antiferroic magnetic dipoles induces ferroic magnetic multipoles, as probed by polarized neutron diffraction. We further identify a microscopic model of altermagnetism that directly relates the $g$-wave multipole and the $g$-wave spin splitting. Through direct observation and quantification of multipoles, this study provides a real-space fingerprint of altermagnetism and establishes a general probe of hidden multipole order in quantum materials.
