Pankaj B. Kaul, Jan Karthein, Jonas Buchhorn, Taizo Kawano, Taisei Usubuchi, Jun Ishihara, Nicolas Rotaru, Patrick Del Vecchio, Omar Concepción, Z. Ikonić, Detlev Grützmacher, Qing‐Tai Zhao, Oussama Moutanabbir, Makoto Kohda, Thomas Schäpers, Dan Buca
The nascent group IV GeSn alloys are highly attractive for spintronics applications, including quantum computing, due to their ability to enable highly scalable fabrication and all-electrical spin manipulation. In this work, we conduct an in-depth study of a two-dimensional hole gas in a Ge/GeSn quantum well, exhibiting the integer quantum Hall effect and distinct Shubnikov-de Haas oscillations. Emphasis is given to the determination of the Landé g-factor and its pronounced anisotropy in this two-dimensional system, revealing values significantly higher than those in conventional Ge or SiGe/Ge systems. Moreover, by modeling the spin-orbit interaction using the Iordanskii-Lyanda-Geller-Pikus theory, crucial cubic Rashba spin-orbit interaction coefficients, are extracted and their significance is highlighted. This work provides the experimental validation of the theoretically predicted enhancements in spin-orbit interaction and g-factors in GeSn alloys compared to Ge. Additionally, it delivers essential parameters for the design of hole spin devices, such as hole qubits, utilizing GeSn-based structures on the Si platform. GeSn alloys hold promise for spintronics and quantum computing due to their scalable fabrication and spin manipulation capabilities. Here, the authors study a two-dimensional hole gas in a Ge/GeSn quantum well, revealing enhanced spin-orbit interactions and g-factors, providing key insights for designing GeSn-based spintronic devices.