Circular dichroism of magnetophonon resonance in doped graphene

Electric field-induced valley degeneracy lifting in uniaxial strained graphene: Evidence from magnetophonon resonance

“…Several studies have given evidence of the electron concentration dependence of the MPR 7,10,15,19 . This dependence is shown figure 4 where we plot the frequency shifts and the broadening of the LO and TO modes for different Fermi energy value.…”

“…This dependence was proposed as a probe to measure the strength of the electron-phonon coupling and to resolve the phonon polarization 10 . Several magneto-Raman measurements have given evidence of the predicted fine structure properties of the MPR of the graphene G band 5,[11][12][13][14][15][16][17] and in particular its filling factor and light polarization dependences. The most pronounced effect of MPR was found, at high magnetic field, for the inter-LL transitions 0 → 1 and −1 → 0 10,15,17 .…”

“…Recently, the filling factor dependence of the MPR was studied by controlling the position of the Fermi level in gated graphene 19,20 . Some puzzling features of the measured MPR structures remain unsolved 15,17 . In particular, the appearance of an additional component in the MPR structure 17 is still not clearly understood.…”

Electrical Switch to the Resonant Magneto-Phonon Effect in Graphene

“…This interaction manifests itself through the magneto-phonon resonance, a series of avoided crossings between the phonon mode and the electronic excitation spectrum each time a ∆|n| = ±1 inter Landau excitation is tuned to the phonon energy. [9][10][11][12][13][14] Magneto-phonon resonance has also been observed in multi-layer graphene specimens, 15 in bulk graphite for both H and K point carriers 16,17 and is now a tool to study the electron-phonon interaction and to perform the Landau level spectroscopy of unknown systems. At the resonance, the splitting energy depends on the effective oscillator strength of the electronic excitation which is determined by the strength of the magnetic field and by the occupancy of the initial and final Landau levels implied in the excitation.…”

“…Up to now, most magneto-Raman scattering experiments have been performed on graphene specimens with a fixed carrier density n s . 13,14 Recently, Remi et al 18 reported on unpolarized Raman scattering experiments on a gated graphene sample, at B = 12.6 T, in the non-resonant regime.…”