Combining plasmonics with magneto-optical materials introduces nanoscaleinteractions between light fields and magnetisation, hence opening up the possibility of using one of these fields to control the other. In this talk I will give an introduction to magneto-plasmons which, at planar interfaces, are known to exhibit non-reciprocal propagation i.e. the wave vectors for left and right propagation are unequal.

Furthermore I will discuss my work on surface plasmons in metal-insulator-metal (MIM)  slot waveguides. In a MIM waveguide with magnetic dielectric the symmetry between the upper and lower interfaces is broken by the introduction of the magnetic field; the balance between the field distributions on the two interfaces can be controlled by the applied field. As a result an external magnetic field can switch on and off the coupling of an electric dipole to the surface plasmon cavity waveguide modes. In addition I will show that both the total emission of radiation from the cavity and the distribution of the far-field radiation is strongly modified by tuning the magnetisation of the MIM structure.