Correlated few-electron states in vertical double-quantum-dot systems

The electronic properties of semiconductor, vertical, double-quantum-dot systems with few electrons are investigated by means of analytic, configuration-interaction, and mean-field methods. The combined effect of a high magnetic field, electrostatic confinement, and interdot coupling, induces a class of few-electron ground states absent in single quantum dots. In particular, the role played by the isospin (or quantum-dot index) in determining the appearance of ground states is analyzed and compared with the role played by the standard spin.