Theory of cyclotron resonance lineshape for an electron-impurity system in two dimensions

Abstract

Using the proper connected diagram expansion which incorporates the quasi-particle effect in a natural manner, we calculated the cyclotron resonance width Γ and frequency shift Δ in the extreme quantum limit, (a) Δ = 0 for any form of interaction potential, (b) Γ ∝ n I 1 2 B 1 2 for a short range interaction, and (c) Γ = π 1 2 ze 2k −1n −1n I 1 2 for the unscreened Coulomb interaction, are obtained in the weak coupling approximation. The result (a) and the field ( B)- and concentration ( n I )-dependence in case (b) are in satisfactory agreement with experimental data on the Si space-charge layers at the surface carrier densities higher than 1 × 10 12cm -2 and at liquid helium temperatures, where the main source of relaxation is thought to arise from a short-range interaction.