Electron spin relaxation in GaAs quantum dot systems - The role of the hyperfine interaction

TL;DR

This paper investigates electron spin relaxation in GaAs quantum dots, emphasizing the hyperfine interaction with nuclear spins and how magnetic fields influence relaxation rates, especially in asymmetric double dot systems.

Contribution

It provides numerical analysis of spin relaxation rates considering hyperfine interactions and phonon effects, highlighting the impact of electron correlations and energy differences.

Findings

Low relaxation rates in highly asymmetric double dots across various magnetic fields.

Strong dependence of relaxation rates on electron correlations and energy differences.

Phonon interactions are crucial for energy dissipation in spin relaxation.

Abstract

We present numerical results for electron spin relaxation rates for single and laterally coupled double GaAs quantum dots in a perpendicular magnetic field. As source of spin relaxation we consider hyperfine interaction with the nuclear spins in the GaAs substrate. Due to the differences in the energy scales of the nuclear and electronic Zeeman energies, the phonon bath system has to be taken into account for energy dissipation. The corresponding transition rates of second order show strong dependencies on correlations between the electrons and the electronic energy differences, and hence on the magnetic field. For a highly asymmetric double dot we have found a relatively low second order electron spin relaxation rate for a wide range of magnetic fields.