Physics and Astronomy Colloquium

The rapid development in nanotechnology gives us direct access to the quantum world. While we seek to implement real-world structures for quantum information technology we are still in the process of understanding of fundamental physics within the “nano-world”. Today we are able to design solid state quantum structures for experiments which have long been known as “Gedankenexperiments” since our understanding of quantum mechanics. Combining single quantum objects to a more complex quantum system is one particular issue. Here, I will review one most simple example: connected quantum conductors. Coupling phenomena such as wave function hybridization can occur in the coherent electron transport in dual electron waveguide structures realized as quantum wires. Operation at liquid helium temperature and above is demonstrated. Mode coupling between degenerate one-dimensional subbands depends on the symmetry of the confining potential and the coupling strength.