Temperature dependence of the cyclotron-resonance linewidth and effective mass in GaAs/${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$${\mathrm{Al}}_{\mathit{x}}$As square-well structures

The cyclotron-resonance linewidth (CRLW) is calculated in GaAs/${\mathrm{Ga}}_{1\mathrm{-}\mathit{x}}$${\mathrm{Al}}_{\mathit{x}}$As single-quantum-well structures in the temperature range 1 K<T<300 K. Contributions to the CRLW due to electron–acoustic-phonon and electron–short-range-impurity interactions are treated on equal footing within the Green’s-function formalism. Frequency-dependent self-energies of the above couplings are determined self-consistently with the density of states of two-dimensional electrons under strong magnetic field at low temperatures. The broadening due to the optical phonons is introduced through an elastic-scattering approximation at high temperatures. Our results are compared with available experiments in the low- and high-temperature regimes and good agreement is found. From the real part of the self-energy, we have calculated the electron effective mass as a function of temperature and found that the acoustic-phonon correction is not negligible.