Light scattering by magnons in whispering gallery mode cavities
Light scattering by magnons in whispering gallery mode cavities
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DOI：
10.1103/physrevb.96.094412
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发表时间：
2017-06
影响因子：
3.7
通讯作者：
Sanchar Sharma;Y. Blanter;G. Bauer
中科院分区：
文献类型：
--
作者：
Sanchar Sharma;Y. Blanter;G. Bauer
布里渊光散射是研究磁振子（磁体的元激发）的一种成熟技术。它的效率可以通过聚集光强度的空腔来提高。在这里，我们从理论上研究光子的非弹性散射的磁球，支持光学回音壁模式在一个平面上垂直于磁化。具有低角动量的磁振子在前向方向上散射光，在斯托克斯和反斯托克斯散射强度中具有明显的不对称性，这与早期的研究一致。具有大角动量的磁振子构成Damon-Bubach模式，其被示出为非弹性地反射光。反射光谱包含斯托克斯峰或反斯托克斯峰，取决于磁化方向，这是一个可以通过Damon-Eshbach磁振子的手性来解释的选择规则。可控制的能量转移可以用于通过光来管理磁体的热力学。
Brillouin light scattering is an established technique to study magnons, the elementary excitations of a magnet. Its efficiency can be enhanced by cavities that concentrate the light intensity. Here, we theoretically study inelastic scattering of photons by a magnetic sphere that supports optical whispering gallery modes in a plane normal to the magnetization. Magnons with low angular momenta scatter the light in the forward direction with a pronounced asymmetry in the Stokes and the anti-Stokes scattering strength, consistent with earlier studies. Magnons with large angular momenta constitute Damon-Eschbach modes which are shown to inelastically reflect light. The reflection spectrum contains either a Stokes or anti-Stokes peak, depending on the direction of the magnetization, a selection rule that can be explained by the chirality of the Damon-Eshbach magnons. The controllable energy transfer can be used to manage the thermodynamics of the magnet by light.