Magnetophonon resonance in graphite: High-field Raman measurements and electron-phonon coupling contributions

TL;DR

This study investigates magnetophonon resonance in graphite using high-field Raman spectroscopy up to 45 T, revealing detailed electron-phonon interactions and their magnetic field dependence, including peak shifts, splittings, and anticrossing behaviors.

Contribution

It provides new insights into electron-phonon coupling in graphite under high magnetic fields through detailed Raman measurements and analysis of magnetophonon resonances.

Findings

Observation of interband electronic excitations over broad magnetic field range

Determination of electron-phonon coupling constants at K- and H-points

G peak narrowing at high magnetic fields indicating suppressed electron-phonon interaction

Abstract

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.