Magnetoplasmon excitations in Graphene

Valley and Zeeman Splittings in Multilayer Epitaxial Graphene Revealed by Circular Polarization Resolved Magneto-infrared Spectroscopy

“…The doped graphene layers near the interface are known to have low electron mobility and thus exhibit a smaller Fermi velocity and lower LL transition energies for a given magnetic field. 49,50 In our case, however, the additional σ + -active modes occur at a lower magnetic field (Figure 1a,c). That is, they occur at higher energies if measured in a constant magnetic field, as compared to the σ − -active modes.…”

“…For case (i), the corresponding fitting parameters are v F e = 1.025 × 10 6 m/s, v F h = 0.975 × 10 6 m/s, Δ < = 0.16 meV/T, Δ > = 1.44 meV/√ T , and the coefficient of determination for the fitting to the n = 0 transition is as high as R 2 = 0.98. The slight deviation between the fits to the n = 1 and n = 2 transitions and the experimental data can be attributed to the contribution from electron–electron interactions, as described previously. ,,, The fit for case (ii) only results in small differences in the n = 0 transition, as indicated by the red dashed lines in Figure with Δ > = 0.39 meV/T. Although within the experimental uncertainty, one cannot differentiate the above two cases, it is still insightful to have a closer look at the fitting parameters.…”

“…It is worth noting that asymmetry in magneto-transmission spectra has previously been reported in the CP-resolved measurements of a thin MEG sample (∼5 layers), where a low-energy mode is observed only with σ + polarized light and attributed to the LL n =0 → LL n =1 transition in the doped layers close to the graphene/SiC interface. The doped graphene layers near the interface are known to have low electron mobility and thus exhibit a smaller Fermi velocity and lower LL transition energies for a given magnetic field. , In our case, however, the additional σ + -active modes occur at a lower magnetic field (Figure a,c). That is, they occur at higher energies if measured in a constant magnetic field, as compared to the σ – -active modes.…”

“…The slight deviation between the fits to the n = 1 and n = 2 transitions and the experimental data can be attributed to the contribution from electron− electron interactions, as described previously. 20,46,49,50 The fit for case (ii) only results in small differences in the n = 0 transition, as indicated by the red dashed lines in Figure 3 with Δ > = 0.39 meV/T. Although within the experimental uncertainty, one cannot differentiate the above two cases, it is still insightful to have a closer look at the fitting parameters.…”

Plasmon modes in graphene: status and prospect

“…[173][174][175][176][177][178] In layered and doped graphene structures, the instability and unusual dispersion of magnetoplasmon modes have been studied in recent years, with different approaches. 172,[179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194][195] Magnetoplasmons have been observed in graphene epitaxially grown on SiC. 196 The Drude absorption is transformed to a strong terahertz plasmonic peak due to nanoscale inhomogeneities, such as substrate terraces and wrinkles.…”