Nonlinear properties of ballistic nanoelectronic devices

Advanced lithographic techniques allow the fabrication of strongly confined semiconductor nanostructures in which carriers travel without suffering from inelastic scattering even for bias voltages between the contacts exceeding several 100 mV. In the ballistic nonlinear transport regime, nanoelectronic devices show several electric properties very different from those of diffusive conductors. In this review we focus on recent studies of quantum wire transistors and Y-branch switches realized by electron beam lithography and wet etching of modulation doped GaAs/AlGaAs heterostructures in relation to nanoelectronic applications, such as a quantum wire amplifier, a compact AND gate based on a single Y-branch, feedback coupled bistable switching devices, static memory elements and a novel NAND gate with defined outputs realized by monolithically integrated Y-branches.