增强纳米磁性超材料中的磁光克尔效应与近完美相干吸收
Enhanced Magneto-Optical Kerr Effect in Nano-Magnetic Metamaterials with Near-Perfect Coherent Absorption
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中文总结 AI 辅助
本研究通过相干光学干涉在坡莫合金纳米磁体超表面中实现近完美吸收（>95%），并增强磁光克尔效应，为纳米磁性系统的光控提供通用方案。
中文摘要 AI 辅助
近年来，无需外部磁场即可控制磁性系统的能力引起了广泛关注，其中全光磁开关展现出越来越大的前景。在磁性纳米结构中实现对光-物质相互作用的精细控制对于推进光磁技术至关重要，但由于必须在目标波长下在超薄磁性结构内实现强光学耦合，这仍然具有挑战性。在这里，我们展示了相干光学干涉可以增强图案化磁性超表面中的这种相互作用。坡莫合金纳米磁体阵列被放置在反射背板之上的薄介电间隔层上，形成磁性超表面，其反射波前由纳米磁体几何形状、填充因子和间隔层厚度决定。超表面与背板反射之间的相消干涉产生了近完美吸收，在圆形纳米磁体阵列的仿真和实验中均超过95%。吸收的功率几乎全部耗散在纳米磁体内部，只有百分之几损失在金属背板中。增强的吸收还伴随着更强的磁光克尔效应，这既源于光-纳米磁体相互作用的增强，也源于反射背景的减少。这些结果为在纳米尺度磁性系统中实现高光学吸收和强磁光响应提供了一种通用方法，支持光可寻址自旋电子学、磁传感和全光磁控制的进步。
英文摘要
The ability to control magnetic systems without external magnetic fields has attracted attention recently, with all-optical magnetic switching showing increasing promise. Gaining fine control over light-matter interactions in magnetic nanostructures is essential for advancing opto-magnetic technologies, but remains challenging because strong optical coupling must be achieved within ultrathin magnetic structures at the target wavelength. Here, we show that coherent optical interference can increase this interaction in patterned magnetic metasurfaces. Arrays of permalloy nanomagnets are placed on a thin dielectric spacer above a reflective back-plane, forming a magnetic metasurface whose reflected wavefront is defined by the nanomagnet geometry, fill factor, and spacer thickness. Destructive interference between the metasurface and back-plane reflections yields near-perfect absorption, exceeding 95% for circular nanomagnet arrays in both simulation and experiment. The absorbed power is dissipated almost entirely within the nanomagnets, with only a few percent lost in the metallic back-plane. Enhanced absorption is also accompanied by a stronger magneto-optical Kerr effect, driven by both increased light-nanomagnet interaction and reduced reflected background. These results provide a general approach for achieving high optical absorption and strong magneto-optical response in nanoscale magnetic systems, supporting advances in optically addressable spintronics, magnetic sensing, and all-optical magnetic control.
发表机构
- Imperial College London（帝国理工学院）
机构由 AI 辅助整理，请以论文原文为准。
