We have fabricated a quantum dot single electron transistor based on anAlGaAs/GaAs heterostructure without any modulation doping. Our device is verystable from an electronic perspective, with clear Coulomb blockadeoscillations, and minimal drift in conductance when the device is set to themidpoint of a Coulomb blockade peak and held at constant gate bias. Biasspectroscopy measurements show typical Coulomb 'diamonds' free of anysignificant charge fluctuation noise. We also observe excited state transportin our device.
展开▼
