Magneto-optical conductivity of a topological nodal ring semimetal in a tilted magnetic field

Abstract

The frequency-dependent magneto-optical response of a topological nodal ring semimetal in a tilted magnetic field is studied systematically. Because of its specific low-energy band structure, we find that the magneto-optical response is affected qualitatively by both the strength and direction of the magnetic field. In the clean limit under the magnetic field along the ring axis, the magneto-optical response is investigated analytically, and several meaningful features are presented. For large ring radii, we find an unusual series of peaks in the transverse optical conductivity. As the ring axis tilts away from the magnetic field, the optical transitions are broken by the vertical projection of the magnetic field. For small ring radii, there is mixing of resonant peaks. The magneto-optical conductivities are explained by optical transitions between the underlying Landau level structure. The influence of chemical potential on the magneto-optical conductivities has been investigated correspondingly.