Papadakis Georgia T, Fleischman Dagny, Davoyan Artur, Yeh Pochi, Atwater Harry A
Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, CA, 91125, USA.
Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA, 91125, USA.
Nat Commun. 2018 Jan 18;9(1):296. doi: 10.1038/s41467-017-02589-8.
Harnessing artificial optical magnetism has previously required complex two- and three-dimensional structures, such as nanoparticle arrays and split-ring metamaterials. By contrast, planar structures, and in particular dielectric/metal multilayer metamaterials, have been generally considered non-magnetic. Although the hyperbolic and plasmonic properties of these systems have been extensively investigated, their assumed non-magnetic response limits their performance to transverse magnetic (TM) polarization. We propose and experimentally validate a mechanism for artificial magnetism in planar multilayer metamaterials. We also demonstrate that the magnetic properties of high-index dielectric/metal hyperbolic metamaterials can be anisotropic, leading to magnetic hyperbolic dispersion in certain frequency regimes. We show that such systems can support transverse electric polarized interface-bound waves, analogous to their TM counterparts, surface plasmon polaritons. Our results open a route for tailoring optical artificial magnetism in lithography-free layered systems and enable us to generalize the plasmonic and hyperbolic properties to encompass both linear polarizations.
此前，利用人工光学磁性需要复杂的二维和三维结构，如纳米颗粒阵列和裂环超材料。相比之下，平面结构，特别是介电/金属多层超材料，通常被认为是非磁性的。尽管这些系统的双曲线和等离子体特性已得到广泛研究，但其假定的非磁性响应将其性能限制在横向磁（TM）极化。我们提出并通过实验验证了平面多层超材料中人工磁性的一种机制。我们还证明，高折射率介电/金属双曲线超材料的磁性可以是各向异性的，从而在某些频率范围内导致磁双曲线色散。我们表明，此类系统可以支持横向电极化的界面束缚波，类似于其TM对应物表面等离激元极化激元。我们的结果为在无光刻分层系统中定制光学人工磁性开辟了一条途径，并使我们能够将等离子体和双曲线特性推广到涵盖两种线性极化。
