EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Heterostructures made of single III-V semiconductor nanowires and an in-situ grown superconductor have led to some of the best quality -but still debated- signatures of Majorana end modes in solid state devices. More robust evidence of these modes, such as the topological Kondo effect, parafermions, and Majorana box qubits, is theorized to lie in pairs of nanowires in contact to a superconductor.

Here we show low temperature transport data in quantum devices made of a new double nanowire platform, consisting of two side-by-side InAs nanowires connected by a superconductor bridge deposited without breaking vacuum [1]. Our devices include double Josephson junctions with parallel quantum dots as weak links and double wires fully covered by the superconductor displaying the Little-Parks effect [2,3]. Our initial characterization shows that these novel double nanowire hybrids are viable candidates for more robust demonstrations of Majorana end modes.

[1] Kanne, T; Olsteins; D., Marnauza, M.; Vekris, A.; Estrada Saldaña, J.C.; Loric, S.; Schlosser, R. D.; Ross, D.; Csonka, S.; Grove-Rasmussen, K.; Nygård, J. (2021). Double nanowires for hybrid quantum devices. arXiv 2103.13938. https://arxiv.org/abs/2103.13938v1

[2] Vekris, A.; Estrada Saldaña, J. C.; Kanne, T.; Marnauza, M.; Olsteins, D.; Fan, F.; Li, X.; Hvid-Olsen, T.; Wang, X.; Qiu, X.; Xu, H. Q.; Nygård, J.; Grove-Rasmussen, K. Josephson junctions in double nanowires bridged by in-situ deposited superconductors (preprint).

[3] Vekris, A.; Estrada Saldaña, J. C.; de Bruijckere, J.; Loric, S.; Kanne, T.; Marnauza, M.; Olsteins, D.; Nygård, J.; Grove-Rasmussen, K. Asymmetric Little-Parks Oscillations in double nanowires (preprint).