Measurement of the electron phase relaxation rate in In0.53Ga0.47As: a possible diagnostic test of compositional disorder

The authors present low-field magnetoresistance measurements made at low temperatures (<or=4.2K) on n-type samples of the semiconductor alloy In0.53Ga0.47As doped in excess of the metal-insulator transition. The samples were strongly degenerate at the temperatures of the measurements. The low-field magnetoresistance is found to be governed by quantum interference (weak-localisation) effects. The authors find that good fits to the data are obtained with a phase relaxation time as the sole variable. This time is much shorter than the calculated magnetic or spin-orbit scattering times, supporting their assertion that these are only minor perturbations