Quantum Technologies using Ge and GeSn on Si.

Large scale fabrication using Complementary Metal Oxide Semiconductor compatible technology of semiconductor nanostructures that operate on the principles of quantum transport is an exciting possibility now due to the development of ultra-high mobility hole gases in epitaxial germanium grown on standard silicon substrates. We present here a ballistic transport study of patterned surface gates on strained Ge quantum wells with SiGe barriers, which confirms the quantum characteristics of the Ge heavy hole valence band structure in 1-dimension.
We also present tranport properties of light holes in GeSn quantum well structures grown on stantard Si (001) substrate.
Furthermore we present the current and future measurements taking place using Ge, including spin focusing and majorana fermion studies using superconducting junctions on Ge layers. The experimental results shown here suggests a new area of experimentation in quasi 1D systems, particularly direct measurement of the charge, with implications for possible schemes of topological quantum information processing.