Department von Klitzing - Low Dimensional Electron Systems

This work of art by Fred Ziegler in the entrance hall of the Max Planck Institute for Solid State Research is devoted to the discovery of the quantum Hall effect on 5.2.1980 at the high magnetic field laboratory of the institute in Grenoble. The plastic is an abstraction of the silicon field effect transistor used for magneto transport measurements on a two-dimensional electron gas.

This research formed the basis for many different research projects in low dimensional electron systems performed in the von Klitzing department and partly continued in the Solid State Nanophysics group of Jurgen Smet and the Nanostructuring Lab of Jürgen Weis. The main focus is on electronic properties of 2-, 1-, and 0-dimensional electron systems, in particular the influence of quantum phenomena on the transport and optical response. Measurements in magnetic fields up to B = 20 Tesla and temperatures down to 20 mK are used to characterize systems. The quantum Hall effect is studied by analyzing the electrical breakdown, the time-resolved transport, the edge channels, the behaviour of composite fermions and new incompressible electronic ground states.  Electron-phonon interactions in low-dimensional systems and surface acoustic waves are used to investigate wave vector dependent excitations. Time-resolved photoconductivity, luminescence, and Raman measurements in magnetic fields are methods of characterizing the low dimensional electronic systems. A strong current interest is the preparation of nanostructures either by self-organized growth or by lithographic and synthetic routes and the investigation of coupled low-dimensional electronic systems. State-of-the -art MBE machines for III-V crystal growth allow the provision of high quality electronic systems useful for research projects on exciton condensation and topological quantum computation. The growth of high quality devices will be continued in close cooperation with the Advanced Semiconductor Quantum Materials group of Werner Wegscheider at ETH Zürich. The experiments are supported within the group by theoretical investigations of the transport and dynamic response of these low-dimensional electronic systems.