InSbAs two-dimensional electron gases as a platform for topological superconductivity
Chung-Ting Ke1,2*, Christian M. Moehle1, Qingzhen Wang1, Candice Thomas3, Di Xiao1, Saurabh Karwal5, Mario Lodari1, Vincent van de Kerkhof1, Ruben Termaat1, Geo rey C. Gardner4, Giordano Scappucci1, Michael J. Manfra3,4, Srijit Goswami1
1QuTech, Delft University of Technology, Delft, Netherlands
2Institute of Physics, Academia Sinica, Taipei, Taiwan
3Department of Physics, Purdue University, West Lafayette, Indiana, USA
4Microsoft Quantum Purdue, Purdue University, West Lafayette, Indiana, USA
5QuTech and Netherlands Organization for Applied Scienti c Research (TNO), Delft University of Technology, Delft, Netherlands
* Presenter:Chung-Ting Ke,
Majorana zero modes have been proposed as building blocks for fault-tolerant quantum information processing. They can be realized in semiconductors with strong spin-orbit interaction coupled to a superconductor. Experimental advances in the fi eld of topological superconductivity have often been triggered by the development of new hybrid material systems. Among these, two-dimensional electron gases (2DEGs) are of particular interest due to their inherent design flexibility and scalability. Here we discuss results on a hybrid 2D platform based on a ternary 2DEG (InSbAs) coupled to in-situ grown Aluminum. The spin-orbit coupling in these 2DEGs can be tuned with the As concentration, reaching values up to 400 meVA, thus exceeding typical values measured in its binary constituents. In addition to a large Lande g-factor around 55 (which is comparable to InSb), we show that the clean superconductor-semiconductor interface leads to highly transparent Josephson junctions and a hard induced superconducting gap in the proximitized semiconductor. Using this new platform we demonstrate the basic operation of phase-controllable Josephson junctions, superconducting islands, and quasi-1D systems, prototypical device geometries used to study Majoranas. Our results establish InSbAs/Al 2DEGs as a promising material system to realize topological superconductivity.

Keywords: Majorana zero mode, topological superconductivity, 2D electron gas, InSbAs/Al hybrid material