Dynamic nuclear polarization in a double quantum dot device: electrical induction and detection

Abstract

Abstract We quantify the magnitude, buildup and relaxation dynamics of dynamic nuclear polarization (DNP) in a vertical GaAs double quantum dot device. This is accomplished using electrical techniques in the two‐electron spin‐blockade regime. Measurements are based on realtime electrical control of the relevant two‐electron spindependent energy levels, and observation of DNPinduced current step features at finite external magnetic fields. A simple phenomenological picture is presented to discuss the factors that limit maximum polarization in this system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)