Spin transitions induced by a magnetic field in quantum dot molecules

TL;DR

This paper provides a theoretical analysis of how magnetic fields induce spin transitions in coupled quantum dot molecules, revealing various magnetic phases and their dependence on external parameters.

Contribution

It introduces a detailed numerical study of spin phases in two coupled quantum dots with eight electrons using HF-CI, highlighting microscopic magnetic phase behaviors.

Findings

Identification of quantum Hall ferromagnetic phases at specific filling factors

Discovery of ferrimagnetic phases due to dot coupling

Dependence of spin transitions on magnetic field, Zeeman energy, and detuning

Abstract

We present a theoretical study of magnetic field driven spin transitions of electrons in coupled lateral quantum dot molecules. A detailed numerical study of spin phases of artificial molecules composed of two laterally coupled quantum dots with N=8 electrons is presented as a function of magnetic field, Zeeman energy, and the detuning using real space Hartree-Fock Configuration Interaction (HF-CI) technique. A microscopic picture of quantum Hall ferromagnetic phases corresponding to zero and full spin polarization at filling factors $\nu=2$ and $\nu=1$, and ferrimagnetic phases resulting from coupling of the two dots, is presented.