Scattering mechanisms in state-of-the-art GaAs/AlGaAs quantum wells

Motivated by recent breakthroughs in molecular beam epitaxy of GaAs/AlGaAs quantum wells [Y. J. Chung et al., Nat. Mater. 20, 632 (2021)], we examine contributions to mobility and quantum mobility from various scattering mechanisms and their dependencies on the electron density. We find that at lower electron densities, n(e) less than or similar to 1 x 10(11) cm(-2), both transport and quantum mobility are limited by unintentional background impurities and follow a power-law dependence, proportional to n(e)(alpha), with alpha approximate to 0.85. Our predictions for quantum mobility are in reasonable agreement with an estimate obtained from the resistivity at filling factor nu = 1/2 in a sample of Y. J. Chung et al. with n(e) = 1 x 10(11) cm(-2). Consideration of other scattering mechanisms indicates that interface roughness (remote donors) is likely a limiting factor of transport (quantum) mobility at higher electron densities. Future measurements of quantum mobility should yield information on the distribution of background impurities in GaAs and AlGaAs.