IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, E-28760, Tres Cantos, Madrid, Spain.
Nanoscale. 2014 Apr 7;6(7):3737-41. doi: 10.1039/c3nr05889a.
In this work we analyse the magnetic field effects on the chirooptical properties of magnetoplasmonic chiral structures. The structures consist of two-dimensional arrays of Au gammadions in which thin layers of Co have been inserted. Due to the magnetic properties of the Au/Co interface the structures have perpendicular magnetic anisotropy which favours magnetic saturation along the surface normal, allowing magnetic field modulation of the chirooptical response with moderate magnetic fields. These structures have two main resonances. The resonance at 850 nm has a larger chirooptical response than the resonance at 650 nm, which, on the other hand, exhibits a larger magnetic field modulation of its chirooptical response. This dissimilar behaviour is due to the different physical origin of the chirooptical and magneto-optical responses. Whereas the chirooptical effects are due to the geometry of the structures, the magneto-optical response is related to the intensity of the electromagnetic field in the magnetic (Co) layers. We also show that the optical chirality can be modulated by the applied magnetic field, which suggests that magnetoplasmonic chiral structures could be used to develop new strategies for chirooptical sensing.
在这项工作中，我们分析了磁场对磁等离子体手性结构的手性光学性质的影响。这些结构由二维的 Au 伽马形排列组成，其中插入了薄的 Co 层。由于 Au/Co 界面的磁性质，这些结构具有垂直磁各向异性，有利于沿表面法线的磁饱和，允许用中等强度的磁场来调制手性光学响应。这些结构有两个主要的共振。850nm 处的共振具有比 650nm 处更大的手性光学响应，而后者则表现出对手性光学响应的更大的磁场调制。这种不同的行为是由于手性光学和磁光响应的不同物理起源。手性光学效应是由于结构的几何形状引起的，而磁光响应则与磁场（Co）层中的电磁场强度有关。我们还表明，光学手性可以通过施加的磁场来调制，这表明磁等离子体手性结构可以用于开发手性光学传感的新策略。
