Splitting of Surface Plasmon Frequencies of Metal Particles in a Nematic Liquid Crystal

We calculate the effective dielectric function for a suspension of small metallic particles immersed in a nematic liquid crystal (NLC) host. For a random suspension of such particles in the dilute limit, we calculate the effective dielectric tensor exactly and show that the surface plasmon (SP)resonance of such particles splits into two resonances, polarized parallel and perpendicular to the NLC director. At higher concentrations, we calculate this splitting using a generalized Maxwell-Garnett approximation, which can also be applied to a small metal particle coated with NLC. To confirm the accuracy of the MGA for NLC-coated spheres, we also use the Discrete Dipole Approximation. The calculated splitting is comparable to that observed in recent experiments on NLC-coated small metal particles.