Magnetophonon resonance in graphite: High-field Raman measurements and   electron-phonon coupling contributions
  We perform Raman scattering experiments on natural graphite in magnetic fields up to 45 T, observing a series of peaks due to interband electronic excitations over a much broader magnetic field range than previously reported. We also explore electron-phonon coupling in graphite via magnetophonon resonances. The Raman G peak shifts and splits as a function of magnetic field, due to the magnetically tuned coupling of the E2g optical phonons with the K- and H-point inter-Landau-level excitations. The analysis of the observed anticrossing behavior allows us to determine the electron-phonon coupling for both K- and H-point carriers. In the highest field range (>35 T) the G peak narrows due to suppression of electron-phonon interaction. 
Y. Kim, Y. Ma, A. Imambekov, N. G. Kalugin, A. Lombardo, A. C.   Ferrari, J. Kono, and D. Smirnov
cond-mat.mes-hall cond-mat.mtrl-sci