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Low-dimensional Electron Systems

Working Group 2.53

Profile

The working group examines of low-dimensional electron systems with focus on possible applications in quantum metrology. One mayor topic it the controlled transport of single electrons in semiconductor nanostructures. Single-electron pumps are a promising candidate for a direct realization of the base unit ampere based on the elementary charge for the revised international unit system SI. Further applications of single-electron sources are expected in the new research area single-electron quantum optics which is expected to provide new tools for quantum technology. The high quality AlGaAs/GaAs heterostructures needed for this research are grown within the working group using two molecular beam epitaxy systems. Achieved mobilities of up to 12 million cm2/Vs testify the high quality of the grown materials. Furthermore, heterostructures from these epitaxy systems are used to fabricate semiconductor devices for other metrological applications, e.g. quantum Hall resistance standards (Opens internal link in current windowDepartment 2.6) or low temperature GaAs sheets for femtosecond Measurement Techniques (Opens internal link in current windowWorking Group 2.54). Another research topic is the growth of monolayer graphene by sublimation-epitaxy on SiC for improved quantum standards of the dc and ac electrical resistance (Opens internal link in current windowDepartment 2.6).

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Research/Development

  • Fabrication and optimization of quantum Hall devices for the realization of the unit of electrical resistance (dc and ac)

  • Fabrication of low-dimensional electron systems by different epitaxy methods and nanolithography

  • Growth of large area graphene sheets by epitaxy

  • Mechanisms of transport and errors in single-electron pumping

  • Complex integrated single-electron transport circuits

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Services

Currently the working group low dimensional electron systems offers now services.

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