Phase-Coherent Transport in GeSn Alloys on Si

Abstract

Germanium-Tin (GeSn) is a novel semiconductor Group IV alloy that can be tuned from indirect to direct bandgap semiconductors by adjusting the Sn content. This property makes this alloy class attractive for integrated photonic applications and high-mobility electronic devices. In this work, the GeSn alloy properties are investigated in the view of applications fields such as spintronics and quantum computing. Using low-temperature magneto-transport measurements, electron interference effects and deriving typical mesoscopic benchmark parameters such as the phase-coherence length in GeSn-based Hall bar structures for Sn concentrations up to 14 at.% is investigated. Furthermore, Shubnikov–de Haas oscillations provide direct access to the effective mass of the Γ-valley electrons as well as the charge carrier mobility. This work provides a new insight into advanced group IV alloys desired for the study of spin dynamics and its quantum computing applications.