Abstract:
The conditions for the appearance of conical singularities in a magnetically ordered crystal in the presence of dichroism, birefringence, and magneto-optical activity have been considered. The possibility of the existence of singularities such as a nodal point, cusp, and point of contact has been demonstrated. The relation of the topological index of the closed singular line to the indices of the $C$ points lying inside the contour has been revealed. Estimates have been made for the YIG:Bi crystal.
Citation:
V. S. Merkulov, “On possible conical singularities in magneto-optics”, Pis'ma v Zh. Èksper. Teoret. Fiz., 94:5 (2011), 383–386; JETP Letters, 94:5 (2011), 353–355