Classical magnetotransport in a parabolic quantum well with a strong intersubband scattering

摘要

Classical magnetotransport coefficients were studied in a parabolic quantum well (PQW) structure with two subbands occupied which occupancies were determined using the Shubnikov-de Haas effect. Unexpectedly, a very low magnetoresistivity effect was observed in compedson with what was predicted from the classical point of view for a system with two kinds of carriers possessing high mobilities around 10-20 m~2 V~(-1) s~(-l). It was shown that methods, including the mobility spectrum technique, based on multilayer approach were inconsistent to describe the magnetotransport in a PQW system because of a strong intersubband scattering. For analysis of the data, a theoretical approach was developed on the basis of solution of the Boltzmann kinetic equation and corresponding formulae were derived employing clearly understood physical parameters of intra-and intersubband scattering frequencies. Based on this theoretical approach the scattering frequencies were deduced from the experimental data. In the PQW the intersubband scattering was much stronger than the intrasubband scattering and it determined the main features of the magnetotransport coefficients.