The two electron artificial molecule

TL;DR

This paper provides exact classical and quantum solutions for a two-electron system in coupled quantum dots, revealing structural transitions and spin oscillations affected by inter-dot distance and magnetic field.

Contribution

It offers the first exact analysis of the classical and quantum behavior of two coupled quantum dots, including structural transitions and spin dynamics.

Findings

Classical system shows a second order structural transition.

Quantum system's transition is smeared and shifted to lower d.

Spin oscillations are shifted and quenched with increasing d.

Abstract

Exact results for the classical and quantum system of two vertically coupled two-dimensional single electron quantum dots are obtained as a function of the interatomic distance (d) and with perpendicular magnetic field. The classical system exhibits a second order structural transition as a function of d which is smeared out and shifted to lower d values in the quantum case. The spin-singlet - spin-triplet oscillations are shifted to larger magnetic fields with increasing d and are quenched for a sufficiently large interatomic distance.