| dc.description |
We consider the surface polaritons at the interface of an antiferromagnet with a metal, predict the effect of such modes on the far-infrared spectrum of an antiferromagnetic film deposited on a metal, and discuss how they may be used to aid the detection of magnon features experimentally. We examine the particular example of an film deposited on a metal substrate. This type of structure may be used to represent many ferromagnet/antiferromagnet bilayer systems, since the ferromagnetic layers of such systems are frequently metallic and, furthermore, do not contribute to the far-infrared magnon spectrum. The associated surface polaritons are unusual for a number of reasons. Firstly, they extend down to zero wavevector, so, in contrast to most surface polariton modes, they should be observable in simple oblique-incidence reflectivity. Secondly, modes can exist in both s and p polarization. Thirdly, the modes show significant shifts from the simple surface polariton frequencies when the film becomes thin. Fourthly, the p-polarization modes show up strongly even for very thin films. Therefore, by choosing the correct geometry, one should be able to enhance considerably the far-infrared spectral features associated with magnon modes in such films. |
