Quantitative modeling of spin relaxation in quantum dots

TL;DR

This paper presents a comprehensive numerical approach to model spin relaxation in two-electron quantum dots, incorporating detailed physical effects and comparing results with experimental data.

Contribution

It introduces a numerically exact diagonalization scheme that includes full 3D quantum dot description, various spin-orbit couplings, and magnetic field orientations, advancing the modeling accuracy.

Findings

Good agreement with experimental singlet-triplet energy splitting.

Accurate prediction of spin relaxation rates.

Analysis of effects of spin-orbit interactions and magnetic field angles.

Abstract

We use numerically exact diagonalization to calculate the spin-orbit and phonon-induced triplet-singlet relaxation rate in a two-electron quantum dot exposed to a tilted magnetic field. Our scheme includes a three-dimensional description of the quantum dot, the Rashba and the linear and cubic Dresselhaus spin-orbit coupling, the ellipticity of the quantum dot, and the full angular description of the magnetic field. We are able to find reasonable agreement with the experimental results of Meunier et al. [Phys. Rev. Lett. 98, 126601 (2007)] in terms of the singlet-triplet energy splitting and the spin relaxation rate, respectively. We analyze in detail the effects of the spin-orbit factors, magnetic-field angles, and the dimensionality, and discuss the origins of the remaining deviations from the experimental data.