Abstract
The surface plasmon polaritons (SPPs) are well-known electromagnetic response that is collective electron oscillations, and are the coupling between electrons and photons. From Maxwell’s equations, it is reasonable to consider a magnetic analog – magnetic surface polaritons (MSPs). The MSPs are the coupling between magnons and photons. To our knowledge, the MSPs have been studying for 50 years, and their theory was well developed. However, only a few experiment of the MSPs were demonstrated. The reason mainly stems from that the magnetic response in naturally occurring medium exists at frequency below THz. Accordingly, we need a big sample that may make measurement of the MSPs difficult. Importantly, the strong magnetic response exists at sufficiently low temperature (i.e. antiferromagnet) or at applied static magnetic field (i.e. ferromagnet). In a consequence, these conditions inevitably make observation of the MSPs difficult. Recently, an artificial medium is rapidly developing. Such artificial medium is composed of subwavelength unit cells and allows a variety of unprecedented electromagnetic responses such as inverse Snell’s law, invisible electromagnetic cloak, and meta-surface. Nowadays, the artificial medium is termed as metamaterials. The magic of the metamaterials is that the constitutive parameters of metamaterials no longer depend on the inherent characteristics of atom or electrons of medium) but on the geometrical structure of unit cell. The property of geometrical structure will make electromagnetic response of metamaterials scalable, and hence the electromagnetic responses can be artificially tailored by designing geometrical structure. In our study, we will demonstrate the artificial MSPs to “live” at room temperature and at no applied static magnetic field, which can be realized by means of our designed metamaterials, and we call our design planar biaxial metamaterials (PBMM). In addition, we derive the general dispersion equation of the MSPs that guides us how to design the PBMM. We expect that the artificial MSPs are applicable to the biosensor, optical antenna, wireless energy transfer, and so on.