Single-and poly-crystalline copper wires with diameters down to 30 nm are grown in etched ion-track membranes. Individual nanowires are isolated and contacted by means of optical lithography. Electronic transport properties and oxidation processes are investigated. Depending on the oxidation state, the wire resistance varies between a few hundred ohms and several megaohms, enabling its usage as metallic or semiconducting structural elements for devices on the nanometer scale.

We present an integrated nanoelectromechanical circuit designed for achieving ultrasensitive displacement detection. It consists of a suspended quantum dot defined in the two-dimensional electron system of an AlGaAs/GaAs heterostructure and a mechanical resonator located in close vicinity. Operation of the individual components is demonstrated: Mechanical as well as transport properties of the resonator and the electron system are specified, respectively. Coulomb blockade in a freely suspended quantum dot is revealed. The data are used to estimate the maximum displacement sensitivity of the device to be 0.029 Å/Hz.

We present fabrication and measurements of gated suspended low-dimensional electron systems. The core component of the device is a low-dimensional electron gas embedded in a free-standing beam processed from a GaAs/AlGaAs heterostructure. The dimensionality of the electronic system is fully controlled by a number of gating electrodes on the suspended membranes. Operation in the quantum Hall regime, in the one-dimensional case, and as zero-dimensional quantum dots is demonstrated. The resulting devices can be applied as ultrasensitive bolometers and as nanoelectromechanical circuits that reach the ultimate limits of displacement detection.