Theory of anisotropic exchange in laterally coupled quantum dots

TL;DR

This paper investigates how spin-orbit coupling affects two-electron spectra in lateral quantum dots, revealing that exchange interaction remains unaffected at zero magnetic field and introducing an effective Hamiltonian for magnetic field conditions.

Contribution

It provides an analytical and numerical analysis of anisotropic exchange effects and proposes a new effective spin Hamiltonian for modeling spin dynamics under magnetic fields.

Findings

Exchange interaction unaffected by spin-orbit coupling at zero magnetic field

Anisotropic exchange appears at finite magnetic fields

Proposes an accurate effective spin Hamiltonian for spin dynamics

Abstract

The effects of spin-orbit coupling on the two-electron spectra in lateral coupled quantum dots are investigated analytically and numerically. It is demonstrated that in the absence of magnetic field the exchange interaction is practically unaffected by spin-orbit coupling, for any interdot coupling, boosting prospects for spin-based quantum computing. The anisotropic exchange appears at finite magnetic fields. A numerically accurate effective spin Hamiltonian for modeling spin-orbit-induced two-electron spin dynamics in the presence of magnetic field is proposed.