论文标题
旋转波的光线散射无法接近自由空间
Brillouin Light Scattering of Spin Waves Inaccessible with Free-Space Light
论文作者
论文摘要
微焦点brillouin光散射是一种强大的技术，用于材料中基本激发的光谱和空间表征。但是，光线的势头很小，将可访问的激发限制在布里渊区的中心。在这里，我们利用了在原型的Ferrimagnet Yttrium Iron Garnet上制造的金属纳米antena，以证明从大波形向量，高频旋转波动激发型从自由空间光中无法获得的高频旋转波激发的可能性。天线促进了电磁场的亚划分限制，从而增强了局部场强度并产生的动量成分明显大于自由空间光的动量成分。我们的方法可以访问对于快速纳米磁性设备重要的高频自旋波，并且可以推广到其他类型的激发和光散射技术。
Micro-focus Brillouin light scattering is a powerful technique for the spectroscopic and spatial characterization of elementary excitations in materials. However, the small momentum of light limits the accessible excitations to the center of the Brillouin zone. Here, we utilize a metallic nanoantenna fabricated on the archetypal ferrimagnet yttrium iron garnet to demonstrate the possibility of Brillouin light scattering from large-wavevector, high-frequency spin wave excitations that are inaccessible with free-space light. The antenna facilitates sub-diffraction confinement of electromagnetic field, which enhances the local field intensity and generates momentum components significantly larger than those of free-space light. Our approach provides access to high frequency spin waves important for fast nanomagnetic devices, and can be generalized to other types of excitations and light scattering techniques.
