Quantum Information Protectorates in Coupled Quantum Dot Exchange Gates

TL;DR

This paper investigates how vortex binding and state mixing in a two-electron quantum dot molecule under magnetic fields can protect quantum information by inducing anticrossings that stabilize spin states.

Contribution

It reveals the mechanism of vortex-induced spin transitions and anticrossing phenomena as a form of quantum information protection in coupled quantum dots.

Findings

Electrons bind to vortices, causing spin transitions.

Anticrossings protect quantum information in spin states.

Low energy states exhibit mixing of vorticity modes.

Abstract

Using exact diagonalization we study the low energy Hilbert space of the two-electron, two-quantum dot artificial molecule under a perpendicular magnetic field. We show that electrons bind to vortices to induce several spin transitions among ground states. Furthermore, the lowest excited states of either even or odd vorticity mix, opening an anticrossing which protects the quantum information stored in the spin states of the strongly correlated quantum dot molecule.