Anisotropy of spin splitting and spin relaxation in lateral quantum dots

TL;DR

This paper investigates how spin splitting and relaxation in lateral quantum dots depend on magnetic field strength and orientation, revealing anisotropic behaviors influenced by spin-orbit coupling and g-factor variations.

Contribution

It provides a detailed analysis of anisotropic spin splitting and relaxation rates in lateral quantum dots under strong magnetic fields, highlighting the effects of crystalline anisotropy and quantum dot geometry.

Findings

Spin splitting shows nonlinear magnetic field dependence due to g-factor and spin-orbit effects.

Spin relaxation rate is anisotropic and increases with magnetic field strength.

Relaxation can be significantly faster when magnetic field is aligned along [100] direction.

Abstract

Inelastic spin relaxation and spin splitting $\epsilon_{\mathrm{s}}$ in lateral quantum dots are studied in the regime of strong in-plane magnetic field. Due to both g-factor energy dependence and spin-orbit coupling $\epsilon_{\mathrm{s}}$ demonstrates a substantial non-linear magnetic field dependence similar to that observed by R.Hanson \textit{et al} [Phys. Rev. Lett. \textbf{91}, 196802 (2003)]. It also varies with the in-plane orientation of magnetic field due to crystalline anisotropy of spin-orbit coupling. Spin relaxation rate is also anisotropic, the anisotropy increasing with the field. When the magnetic length is less than the 'thickness' of GaAs dot, the relaxation can be order of magnitude faster for $\mathbf{B}% \Vert\lbrack100]$ than for $\mathbf{B\Vert}[110]$.