Possible Interpretation of Cyclotron Resonance Absorption in Graphite

An interpretation of cyclotron absorption experiments in graphite is presented. Evidence is given for the existence of a majority and minority hole, and a majority and minority electron. The masses for the majority hole and electron are $\sim 0.07 m_0$ and $\sim 0.05 m_0$, respectively. The masses for the minority hole and electron are $0.028m_0$ and $0.015m_0$, respectively. Strong indications of second and third harmonic cyclotron resonances for the minority carriers, and weaker indications of harmonics for the majority carriers are noted. Based on the assumption that these lines are correctly interpreted as harmonics, selection rules for harmonics of the cyclotron resonance exclude certain positions of the band extrema in the Brillouin zone.