无磁性材料的光子磁性与交替磁性

中文摘要 AI 辅助

磁性是固体的基本属性，源于磁性原子电子自旋的集体排列，近来交替磁性的发现拓展了磁性的范畴，它是一种由对称性驱动的相，区别于铁磁性和反铁磁性。最初在光子系统中模拟交替磁性的研究主要利用材料的磁光响应，但这类材料存在固有的频率限制，难以将光子交替磁性拓展到光学领域，从而限制了材料选择和光学应用。本文通过群论对称性分析建立了光子磁性的微观框架，定义了电子自旋和磁性原子的光子对应物，该方法可在完全由无磁介电材料构成的结构化光学晶格中实现光子铁磁、反铁磁和交替磁相，既拓展了光子磁性的概念，又突破了材料和频率限制。分析模型、数值模拟和实验测量揭示了与电子对应物直接对应的自旋-动量锁定，在电信波长（约1550 nm）处呈现d、g和i波圆二色性（CD）分裂带。这些结果表明，仅通过对称性和模式耦合即可在光子系统中重构交替磁序乃至更广泛的磁性，为自旋依赖的光调控以及介电光子晶体中量子磁性现象的玻色子模拟开辟了新途径。

英文摘要

Magnetism, a fundamental property of solids arising from the collective alignment of electronic spins of magnetic atoms, has recently been expanded by the discovery of altermagnetism, a symmetry-driven phase distinct from both ferromagnetism and antiferromagnetism. Initial efforts to emulate altermagnetism in photonic systems are also being pursued, primarily through the magneto-optic response of materials; however, their intrinsic frequency limitations pose challenges for extending photonic altermagnetism into the optical regime, thereby restricting their material choices and optical applications. Here, we establish a microscopic framework of photonic magnetism through group theory symmetry analysis, defining photonic counterparts of electron spin and magnetic atoms. This approach enables the realization of photonic ferromagnetic, antiferromagnetic, and altermagnetic phases within structured optical lattices constructed by purely dielectric, nonmagnetic materials, which not only broadens the photonic magnetism concept, but also lifts the material and frequency limitations. Analytical models, numerical simulations, and experimental measurements reveal spin-momentum locking directly corresponding to their electronic analogs, showing d-, g-, and i-wave circular dichroism (CD) splitting bands at telecom wavelengths (around 1550 nm). These results demonstrate that altermagnetic order, and magnetism more broadly, can be reconstructed in photonic systems through symmetry and mode coupling alone, opening a new route towards spin-dependent light control and bosonic analogs of quantum magnetic phenomena in dielectric photonic crystals.

发表机构

• University of California, Berkeley（加州大学伯克利分校）
• Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）

机构由 AI 辅助整理，请以论文原文为准。