Ghost surface polariton in antiferromagnets

Abstract

A surface polariton was predicted in antiferromagnets in a simple geometry. It exhibits interesting characteristics. Its electromagnetic fields and energy-flux density both oscillate and attenuate with the distance from the surface. It is a ghost surface polariton (GSP) and is a magnetic-field-tunable surface polariton. The branch-interference produces a series of rapidly attenuated fringes. It exists only in an external magnetic field along the easy axis. The attenuated total reflection spectra obtained in the Otto configuration accurately demonstrate this GSP and show its excitation or observation path.