posted on 2021-11-18, 20:44authored byChristian
M. Moehle, Chung Ting Ke, Qingzhen Wang, Candice Thomas, Di Xiao, Saurabh Karwal, Mario Lodari, Vincent van de Kerkhof, Ruben Termaat, Geoffrey C. Gardner, Giordano Scappucci, Michael J. Manfra, Srijit Goswami
Topological superconductivity can
be engineered in semiconductors
with strong spin–orbit interaction coupled to a superconductor.
Experimental advances in this field 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
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 meV Å, thus
exceeding typical values measured in its binary constituents. In addition
to a large Landé g-factor of ∼55 (comparable to that
of InSb), we show that the clean superconductor–semiconductor
interface leads to a hard induced superconducting gap. 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 Majorana zero modes.