Metaphotonics, combining metamaterial (MM) and nanophotonic concepts, offers a unique platform for obtaining an unusual and/or advantageous electromagnetic response on a scale much less than the wavelength, although several practical applications are strongly hampered by the complexity of fabrication of MM devices and the intrinsic subwavelength inhomogeneous response of the MM composite. Recently, much research effort has been focused on the study of photonic devices for magnetic resonance imaging (MRI), one of the cornerstone diagnostics techniques in life science. In the MRI context, we introduce the use of magnetic surface excitations (magnetic localized surface plasmons) supported by a negative-magnetic-permeability MM sphere that results in a significant local enhancement of the MRI signal-to-noise ratio. Using the Mie resonance theory, we show that an increase in the signal-to-noise ratio boost can be obtained by replacing the MM sphere with a homogeneous high-permittivity one of the same radius. Overcoming some of the main MM limiting factors, our results suggest a simple approach for the realization of radio-frequency magnetic metadevices.

中文翻译：

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通过Mie共振模拟局部表面等离激元以增强磁共振成像应用

结合超材料（MM）和纳米光子概念的超光子学，提供了一个独特的平台，可在远远小于波长的范围内获得异常和/或有利的电磁响应，尽管由于MM器件制造的复杂性以及MM复合材料的固有亚波长非均匀响应。最近，许多研究工作集中在用于磁共振成像（MRI）的光子设备的研究上，这是生命科学的基础诊断技术之一。在MRI环境中，我们介绍了使用由负磁导率MM球支撑的磁表面激发（磁局部表面等离激元），从而显着增强了MRI的信噪比。利用三重共振理论 我们表明，通过用相同半径之一的均质高介电常数替代MM球体，可以提高信噪比。克服了一些主要的MM限制因素，我们的结果提出了一种实现射频磁性元设备的简单方法。