Figure 1

(Color online) Relative transmission spectra of the sample A (MEG on C face of SiC) for selected values of the magnetic field. For clarity, successive spectra are shifted vertically by 0.1. Individual transitions discussed in this paper are denoted by vertical arrows.Reuse & Permissions

Figure 2

(Color online) Positions of absorption lines observed in the A sample grown on C-terminated surface of SiC. The spheres correspond to inter-LL transitions in electrically isolated and nearly undoped layers in MEG, having a characteristic $\sqrt{B}$ dependence. The dashed lines show their theoretically expected positions for the Fermi velocity of $v_F=1.02\times {10}^6{\text{ms}}^{-1}$. Origin of the transition denoted by stars, which evolves nearly linearly with $B$, is discussed in the text.Reuse & Permissions

Figure 3

(Color online) Transmission spectra of the sample B taken at various magnetic fields in the far-infrared spectral region. Solid curves represent fits to experimental data (spheres) according to the quasiclassical theory described in the text. For clarity, successive spectra are shifted vertically by 0.1. Vertical arrows indicate position of a relatively broad CR resonance, as obtained from the analysis. The inset shows fitting procedure at $B=10\text{T}$ in detail. The individual transmission curves $T\left(0\right),T\left(B\right),T_{+}\left(B\right)$ and $T_{-}\left(B\right)$ have been plotted to demonstrate their contribution to the final relative change in sample transmission $T\left(B\right)/T\left(0\right)$. Let us note that these curves share a common baseline given by the transmission of the slab without any conducting layer (or away from the resonances) $T_{\text{Slab}}=2n/\left(n^2+1\right)\approx 0.67$.Reuse & Permissions

Figure 4

(Color online) Position of the cyclotron resonance in the sample B as extracted from the fitting experimental curves in Fig. 3, well following the linear in B dependence plotted for the cyclotron mass of $m=0.053m_0$ (full line). For comparison, we also depict positions of intraband (i.e., cyclotron) resonances between LLs with higher indices, $L_n\to L_{n+1}$ $n=6,\dots ,40$ (dotted lines). The inset schematically shows linear in $B$ evolution of CR in highly doped graphene, despite the fact that the individual LLs exactly follow the $\sqrt{B}$ dependence. As we cannot determine the sign of charge of the particles in our nonpolarized transmission experiment, we considered $n$-type doping only in this inset for simplicity.Reuse & Permissions