Time dependent configuration interaction simulations of spin swap in spin orbit coupled double quantum dots

TL;DR

This paper presents time-dependent configuration interaction simulations of spin exchange in spin-orbit coupled double quantum dots, revealing how electron interactions and spin-orbit effects influence spin dynamics and anisotropy.

Contribution

It introduces a numerically exact simulation method accounting for spin-orbit coupling and electron interactions in quantum dots, providing new insights into spin transfer mechanisms.

Findings

Spin exchange is affected by spin precession in an effective SO magnetic field.

Coulomb interaction blocks electron transfer but not spin transfer.

Isotropy of spin swap is restored with equal Dresselhaus and Rashba constants.

Abstract

We perform time-dependent simulations of spin exchange for an electron pair in laterally coupled quantum dots. The calculation is based on configuration interaction scheme accounting for spin-orbit (SO) coupling and electron-electron interaction in a numerically exact way. Noninteracting electrons exchange orientations of their spins in a manner that can be understood by interdot tunneling associated with spin precession in an effective SO magnetic field that results in anisotropy of the spin swap. The Coulomb interaction blocks the electron transfer between the dots but the spin transfer and spin precession due to SO coupling is still observed. The electron-electron interaction additionally induces an appearance of spin components in the direction of the effective SO magnetic field which are opposite in both dots. Simulations indicate that the isotropy of the spin swap is restored for equal Dresselhaus and Rashba constants and properly oriented dots.