Motivated by recent breakthroughs in molecular beam epitaxy of GaAs/AlGaAs quantum wells [Y. J. Chung et al., Nat. Mater. 20, 632 (2021)1476-112210.1038/s41563-021-00942-3], 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, nea1×1011cm-2, both transport and quantum mobility are limited by unintentional background impurities and follow a power-law dependence, a neα, with α≈0.85. Our predictions for quantum mobility are in reasonable agreement with an estimate obtained from the resistivity at filling factor ν=1/2 in a sample of Y. J. Chung et al. with ne=1×1011cm-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.
|Original language||English (US)|
|Journal||Physical Review Materials|
|State||Published - Jun 2022|
Bibliographical noteFunding Information:
Acknowledgments. We thank L. N. Pfeiffer and M. Shayegan for discussions and clarifying the experimental details. Y.H. was partially supported by the William I. Fine Theoretical Physics Institute. M.A.Z. acknowledges support by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award No. ER 46640-SC0002567.
© 2022 American Physical Society.