Calculation of the cyclotron resonance line shape in a wigner crystal

Abstract

The cyclotron resonance absorption spectrum in a Wigner crystal is calculated. Due to band-structure effects, the electrons at different sites have different cyclotron resonance frequencies depending on their spin orientation. To calculate the absorption line shape we consider effects of Coulomb (dipole-dipole) interaction between the excitations at different sites. The averaging over different realizations of the spin arrangement is done within the coherent potential approximation. The results show a crossover from a double-peak spectrum at small filling factors where the dipole-dipole interaction is weak, to a single-peak spectrum at filling factors larger than about 1/6 where the interaction effects are completely dominating. As the electron filling factor is increased further, the absorption line becomes broader due to radiation damping. The results are in good agreement with experiments.