Dynamical spin-spin coupling of quantum dots

TL;DR

This paper predicts a novel, tunable Ising-type spin-spin coupling between quantum dots induced by a rotating magnetic field, enabling controllable entanglement of quantum states.

Contribution

It introduces a new dynamical coupling mechanism between quantum dots, derived through a nested Schrieffer-Wolff transformation, expanding understanding of spin interactions under external fields.

Findings

The coupling is tunable via the rotating magnetic field magnitude.

The new coupling can be comparable to RKKY interaction.

Enables creation of controllable entangled Bell states.

Abstract

We carried out a nested Schrieffer-Wolff transformation of an Anderson two-impurity Hamiltonian to study the spin-spin coupling between two dynamical quantum dots under the influence of rotating transverse magnetic field. As a result of the rotating field, we predict a novel Ising type spin-spin coupling mechanism between quantum dots, whose strength is tunable via the magnitude of the rotating field. The strength of the new coupling could be comparable to the strength of the RKKY coupling. The dynamical coupling with the intristic RKKY coupling enables to construct a four level system of maximally entangled Bell states in a controllable manner.