Multi-Terminal Superconducting Nonequilibrium Device With a Ferromagnetic Screen

• Published in: IEEE transactions on applied superconductivity 2011-06, Vol.21 (3), p.721-723
• Main Authors: Nevirkovets, I P, Chernyashevskyy, O, Ketterson, J B, Pan, A V
• Format: Article
• Language: English
• Subjects: Aluminum; Applied sciences; Devices; Electrical engineering. Electrical power engineering; Electrodes; Electromagnets; Electronics; Exact sciences and technology; Ferromagnet-superconductor structures; Ferromagnetism; Injectors; Josephson junctions; Junctions; Nickel; Niobium; nonequilibrium superconductivity; proximity effect; Screens; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Superconducting devices; Superconducting epitaxial layers; superconducting transistors; Superconductivity; superconductor-insulator-superconductor devices; tunneling; Various equipment and components
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2010.2084551

We have fabricated and characterized double-barrier multi-terminal superconducting transistor-like devices with the Nb/Al/AlO x /Al/Nb/Ni/Al/AlO x /Al/Nb (S 1 IS 2 FIS 3 ) structure, where S, I, and F refer to superconducting, insulating, and ferromagnetic layers, respectively. A thin ferromagnetic Ni layer screens the superconductivity of the middle Nb layer on the injector-barrier side, so that the Nb/Ni bilayer manifests itself as a superconductor in the current-voltage characteristic (I-V curve) of the acceptor S 1 IS 2 junction, but as a normal metal in the I-V curve of the injector S 2 FIS 3 junction. It is shown that this property allows for considerable improvement of the input-output isolation of the quasiparticle-injection devices as compared with that for the formerly reported quiteron.