blockade regime of double GaAs vertical quantum dots. The nuclear Overhauser field
measurement relies on bias voltage control of the interdot spin exchange coupling and
measurement of dc current at variable external magnetic fields. The largest Overhauser field
observed was about 4 T, corresponding to a nuclear polarization≈ 40% for the electronic g
factor typical of these devices,| g*|≈ 0.25. A phenomenological model is proposed to …