Related Experiment Video
Updated: Aug 23, 2025

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
Published on: November 1, 2013
Microscopic Origin of the Effective Spin-Spin Interaction in a Semiconductor Quantum Dot Ensemble
Frederik Vonhoff1, Andreas Fischer1, Kira Deltenre1
1Department of Physics, Technical University Dortmund, Otto-Hahn-Straße 4, 44227 Dortmund, Germany.
Abstract:
We present a microscopic model for a singly charged quantum dot (QD) ensemble to reveal the origin of the long-range effective interaction between the electron spins in the QDs. Wilson's numerical renormalization group (NRG) is used to calculate the magnitude and the spatial dependency of the effective spin-spin interaction mediated by the growth-induced wetting layer. Surprisingly, we found an antiferromagnetic Heisenberg coupling for very short inter-QD distances that is caused by the significant particle-hole asymmetry of the wetting layer band at very low filling. Using the NRG results obtained from realistic parameters as input for a semiclassical simulation for a large QD ensemble, we demonstrate that the experimentally reported phase shifts in the coherent spin dynamics between single- and two-color laser pumping can be reproduced by our model, solving a long-standing open problem of the microscopic origin of the inter-QD electron spin-spin interaction.
Related Concept Videos
Atomic Nuclei: Nuclear Spin State Overview
The Pauli Exclusion Principle
NMR Spectroscopy: Spin–Spin Coupling
Spin–Spin Coupling Constant: Overview
Qualitatively, any spin plus-half nucleus polarizes the spins of its electrons to the minus-half state. Consequently, the paired electron in the hydrogen–carbon bond must...
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
Spin–Spin Coupling: One-Bond Coupling

