A field-induced semiconductor quantum dot defined by a single metallic front-gate

We present studies on the electronic transport in a quantum dot based on a back-gated undoped GaAs/AlGaAs heterostructure. A high-quality two-dimensional electron gas can be induced in the structure by applying a back-gate voltage. The quantum dot is well defined by means of a single metallic frontgate. We observe clear regions of Coulomb blockade and pronounced tunneling peaks in a broad range of source-drain and front-gate voltages. The formation of the quantum dot and energetic evolution of the associated tunneling peaks are studied as a function of the applied front-gate voltage. Excellent agreement to the calculated Coulomb diamond pattern using the 'constant interaction model' is achieved, if a front-gate voltage dependent change of the dot capacitance is taken into account.