Interaction of tunnel-coupled quantum dots in a magnetic field

An artificial molecule formed by two tunnel-coupled quantum dots in a ${\mathrm{G}\mathrm{a}\mathrm{A}\mathrm{s}/\mathrm{A}\mathrm{l}}_x{\mathrm{Ga}}_{1-x}\mathrm{As}$ heterostructure is studied in perpendicular magnetic fields. Coulomb blockade spectroscopy at low temperatures determines how the binding energy of the artificial molecule evolves with magnetic field. The binding energy and the double-dot ground-state energy exhibit mesoscopic fluctuations due to the coupling of electron wave functions on the individual dots.