ABSTRACT

This chapter considers some of the group-theoretical methods which are used for the study of complex media. The discussion is based on the magnetic group theory which includes nonmagnetic groups as a particular case. The chapter considers some symmetries which exist in classical electromagnetic theory based on Maxwell’s equations. Anisotropic and bianisotropic media described by lower discrete groups of symmetry have usually a more number of independent parameters and more complex electromagnetic properties. Artificial composite media can consist of a host material and some inclusions, and may be under external fields and forces. The magnetic group of symmetry of a medium is defined by the symmetry of its particles, their mutual arrangement, the symmetry of the host medium, the symmetry of the external perturbations, as it follows from Curie’s principle of symmetry superposition. The chapter discusses a method of calculation of the second-rank tensor structure for complex and bianisotropic media with a known symmetry.