About the linewidth of cyclotron resonance in band-gap graphene

• The conditions for linear theory of the electromagnetic response in graphene were found.
• The dependence of the cyclotron linewidth on the relaxation time was investigated.
• The dependence of the cyclotron linewidth on the temperature was defined.
• In graphene, cyclotron linewidth was shown to be nonzero in a collisionless regime.

The critical amplitude of circularly polarized electromagnetic wave when the hysteresis of cyclotron absorption takes place, was found for band-gap graphene. The dependence of critical amplitude on the gap value and on the relaxation time was investigated. The conditions of applicability of linear theory describing the electromagnetic response of band-gap graphene in a non-zero magnetic field were found. The power of the circularly polarized electromagnetic radiation absorbed by band-gap graphene in the presence of a magnetic field was calculated. The linewidth of cyclotron absorption was shown to be not zero even for pure band-gap graphene.