Electromagnetic Wave Propagation in Asymmetric Hyperbolic Magnetic Media

Natural hyperbolic magnetic media exist in which optical effects such Goos-Hanchen shifts [1] and negative reflection [2] can be tuned by simply applying external magnetic fields. We discuss how this occurs in antiferromagnets and show that by rotating the easy axis of the crystal, the hyperbolic dispersion is rotated and the angle of refraction is modified and cannot be defined as simply negative and positive as it is done in conventional hyperbolic media. The optical properties (i.e. focusing) derived from the hyperbolic behaviour are also modified. Because the crystal is magnetic all afore mentioned behaviour can be tuned to a different frequency by applying external magnetic fields.

[1] R. Macêdo, T. Dumelow, and R. L. Stamps “Spin canting induced nonreciprocal Goos-Hänchen shifts” Optics Express, 22, 28467 (2014)
[2] R. Macêdo, T. Dumelow, and R. L. Stamps “Tunable Focusing in Natural Hyperbolic Magnetic Media” ACS Photonics 3, 9, 1670-1677, (2016)