Mesoscopic g-factor renormalization for electrons in III-V interacting nanolayers

Abstract

The physics of the renormalization of the effective electron g factor by the confining potential in semiconductor nanostructures is theoretically investigated. The effective g factor for electrons in structures with interacting nanolayers, or coupled quantum wells (QWs), is obtained with an analytical and yet accurate multiband envelope-function solution, based on the linear $8\ifmmode\times\else\texttimes\fi{}8\phantom{\rule{4pt}{0ex}}\mathrm{k}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{p}$ Kane model for the bulk band structure. Both longitudinal and transverse applied magnetic fields are considered and the g-factor anisotropy (i.e., the difference between the two field configurations) is analyzed over the entire space spanned by the two structure parameters: the thickness of the active layers and the thickness of the tunneling barrier separating them. Two-dimensional anisotropy maps are constructed for symmetric and asymmetric InGaAs coupled QWs, with InP tunneling barriers, that reproduce exactly known single-layer or QW results, in different limits. The effects of the structure inversion asymmetry on the mesoscopic g-factor renormalization are also discussed, in particular the negative anisotropies for thin-layer structures. Such multilayer structures form an excellent testing ground for the theory, and the analytical solution presented, which is perfectly consistent over the whole space of parameters, leads to helpful expressions and can guide further research on the mechanisms of this mesoscopic renormalization.