Entanglement in a three spin system controlled by electric and magnetic field

TL;DR

This paper investigates how electric and magnetic fields influence spin entanglement in a triangular quantum dot molecule, revealing how these fields modify correlations, energy levels, and spin delocalization.

Contribution

It provides an explicit relation between concurrence, spin correlations, and chirality, and explores the effects of electric and magnetic fields on entanglement and spin behavior.

Findings

Electric field modifies super-exchange correlations and shifts energy levels.

Electric field can induce monogamy of entanglement with one spin separated.

Magnetic flux causes spin delocalization and circulation of spin supercurrents.

Abstract

We show influence of electric field and magnetic flux on spin entanglement in an artificial triangular molecule build of coherently coupled quantum dots. In a subspace of doublet states an explicit relation of concurrence with spin correlation functions and chirality is presented. The electric field modifies super-exchange correlations, shifts many-electron levels (the Stark effect) as well as changes spin correlations. For some specific orientation of the electric field one can observe monogamy, for which one of the spins is separated from two others. Moreover, the Stark effect manifests itself in different spin entanglement for small and strong electric fields. A role of magnetic flux is opposite, it leads to circulation of spin supercurrents and spin delocalization.