Cyclotron–phonon resonance line-width in monolayer silicene

Abstract

We theoretically observe the cyclotron–phonon resonance (CPR) in monolayer silicene by considering the magneto-optical absorption power (AP) of the system. The AP is calculated utilising the projection operator technique when a static magnetic field is subjected perpendicularly to the plane of the material and the electron–optical phonon scattering is involved. The absorption spectra show the resonance behaviour where the photon energies at resonant peaks satisfy the cyclotron–phonon (CPR) conditions in which the CPR energy depends linearly on the square root of the magnetic field strength. This dependence is similar to that in graphene and different from that in monolayer MoS2 and conventional low-dimensional semiconductors. The dependence of the full-width at half maximum (FWHM) on the magnetic field strength has the laws similar to those obtained for graphene and monolayer MoS2. However, the FWHM value in silicene is two times smaller than it is in graphene and has the same order as it does in monolayer MoS2. At relatively high temperature (T>300 K), the FWHM for phonon emission differs very little from that for phonon absorption and becomes identical in two cases when T>350 K.