1211.6094 (Y. Kim et al.)

Filling-Factor-Dependent Magnetophonon Resonance with Circularly
Polarized Phonons in Graphene Revealed by High-Field Magneto-Raman
Spectroscopy    [PDF]

Y. Kim, J. M. Poumirol, A. Lombardo, N. G. Kalugin, T. Georgiou, Y. J. Kim, K. S. Novoselov, A. C. Ferrari, J. Kono, O. Kashuba, V. I. Fal'ko, D. Smirnov

We perform polarization-resolved Raman spectroscopy on graphene in magnetic fields up to 45T. This reveals a filling-factor-dependent, multi-component anti-crossing structure of the Raman G peak, resulting from magneto-phonon resonances between magneto-excitons and circularly polarized E$_{2g}$ phonons. This structure is explained with a model of Raman scattering taking into account the effects of spatially inhomogeneous carrier densities and strain. This shows that random fluctuations of strain-induced pseudo-magnetic fields lead to increased scattering intensity inside the anti-crossing gap, consistent with the experiment.

View original: http://arxiv.org/abs/1211.6094