Gate-induced electron transfer effects in monolithic Al-Ge-Al nanostructures

Germanium (Ge) is recognized as a highly promising substrate for a broad spectrum of electronic, optical, and quantum applications, owing to its exceptional properties, including high charge carrier mobility, strong spin-orbit coupling, and its behavior as a quasi-direct semiconductor. However, the electron transfer effect in Ge, similar to the Gunn effect in GaAs, which induces negative differential resistance, has received relatively little attention thus far. This is likely due to the requirement for a well-defined material system and device architecture for its realization and usually at low temperatures.