Few-electron double quantum dots

Two tunnel-coupled few-electron quantum dots were fabricated in a GaAs/AlGaAs quantum well. The absolute number of electrons in each dot could be determined from finite-bias Coulomb blockade measurements and gate voltage scans of the dots, and allows the number of electrons to be controlled down to zero. The Zeeman energy of several electronic states in one of the dots was measured with an in-plane magnetic field, and the g-factor of the states was found to be no different from that of electrons in bulk GaAs. Tunnel coupling between dots is demonstrated, and the tunnelling strength was estimated from the peak splitting of the Coulomb blockade peaks of the double dot.