Spin Orientation and Spin Precession in Inversion-Asymmetric Quasi Two-Dimensional Electron Systems

TL;DR

This paper investigates how inversion asymmetry affects spin orientation and precession in quasi-2D electron systems, revealing dependence on crystallographic direction and wave vector, with implications for spintronic device control.

Contribution

It provides a detailed analysis of spin orientation and effective magnetic fields in quasi-2D systems using a comprehensive 8x8 Kane model, considering both bulk and structure inversion asymmetry.

Findings

Spin orientation depends on crystallographic direction.

Effective magnetic field varies with in-plane wave vector.

Results applicable to GaInAs-InP quantum wells.

Abstract

Inversion asymmetry induced spin splitting of the electron states in quasi two-dimensional (2D) systems can be attributed to an effective magnetic field B which varies in magnitude and orientation as a function of the in-plane wave vector k||. Using a realistic 8x8 Kane model that fully takes into account spin splitting because of both bulk inversion asymmetry and structure inversion asymmetry we investigate the spin orientation and the effective field B for different configurations of a quasi 2D electron system. It is shown that these quantities depend sensitively on the crystallographic direction in which the quasi 2D system was grown as well as on the magnitude and orientation of the in-plane wave vector k||. These results are used to discuss how spin-polarized electrons can precess in the field B(k||). As a specific example we consider GaInAs-InP quantum wells.