Single-hole transistor in p-type GaAs∕AlGaAs heterostructures

Abstract

A single-hole transistor is patterned in a p-type, C-doped GaAs∕AlGaAs heterostructure by scanning probe oxidation lithography. Clear Coulomb blockade resonances have been observed at Thole=300mK. A charging energy of ∼1.5meV is extracted from Coulomb diamond measurements, in agreement with the lithographic dimensions of the dot. The absence of excited states in Coulomb diamond measurements, as well as the temperature dependence of Coulomb peak heights indicate that the dot is in the multilevel transport regime. Fluctuations in peak spacings larger than the estimated mean single-particle level spacing are observed.