1304.5415 (Y. Ma et al.)

Effects of Electron-Electron Interactions on Electronic Raman Scattering
of Graphite in High Magnetic Fields    [PDF]

Y. Ma, Y. Kim, N. G. Kalugin, A. Lombardo, A. C. Ferrari, J. Kono, A. Imambekov, D. Smirnov

We report the observation of strongly temperature-dependent, asymmetric spectral lines in electronic Raman scattering spectra of graphite in a high magnetic field up to 45 T applied along the c-axis. The magnetic field quantizes the in-plane motion, while the out-of-plane motion remains free, effectively reducing the system dimension from three to one. Optically created electron-hole pairs interact with, or shake up, the one-dimensional Fermi sea in the lowest Landau subbands. Based on the Tomonaga-Luttinger liquid theory, we show that interaction effects modify the van Hove singularity to the form $(\omega-\Delta)^{2\alpha-1/2}$ at zero temperature. At finite temperature, we predict a thermal broadening factor that increases linearly with the temperature. Our model reproduces the observed temperature-dependent line-shape, determining $\alpha$ to be $\sim$0.05 at 40 T.

View original: http://arxiv.org/abs/1304.5415