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The study of electronic properties of nanoscale systems is motivated by the increasing importance
of quantum effects as electronic devices decrease in size. An important aspect is given by the limitations
of scaling classical electronic devices such as the Metal-Oxide-Semiconductor Field-Effect-Transistor (MOSFET).
Our studies of quantum phenomena aim at finding new ways of information processing. Our current major research
interest is the exploration of ways to implement and control quantum bits (qubits) on the basis of solid state
electronics and thereby lay the ground work for a future quantum information technology. In order to allow quantum
information processing it is necessary to couple an array of such qubits in a controlled way. There exist many interesting
efforts to achieve this task in different areas of physics. However, an important advantage of our solid state based
two-dimensional nanoscale devices is their possible fabrication by well established industrial methods with ever increasing
accuracy. In principal, this allows scalability regarding the number of coupled qubits.

Quantum dots, zero-dimensional systems containing a distinct number of electrons, sometimes referred to as artificial atoms,
are a promising candidate for the realization of qubits. We fabricate quantum dot devices by selectively depleting a
two-dimensional electron system (2DES) embedded within a GaAs/AlGaAs-heterostructure. Application of negative voltages to
nanoscale metal gates on the surface of the heterostructure modulates the local potential and thereby restricts the mobility
of electrons whithin the 2DES beneath these top gates.