TY - JOUR
T1 - Investigation of Current Gain in Superconducting-Ferromagnetic Transistors with High-jc Acceptor
AU - Nevirkovets, Ivan P.
AU - Shafraniuk, Serhii E.
AU - Chernyashevskyy, Oleksandr
AU - Yohannes, Daniel T.
AU - Mukhanov, Oleg A.
AU - Ketterson, John B.
N1 - Publisher Copyright:
© 2002-2011 IEEE.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/6
Y1 - 2017/6
N2 - We report the results of a study of the current gain in high Josephson critical current density (jc ) superconductingferromagnetic transistors with the SISFIFS structure [where S, I, and F denote a superconductor (Nb), an insulator (AlOx), and a ferromagnetic material (permalloy, Py), respectively]. The Nb/AlOx/Nb trilayer, which serves as the acceptor (SIS) junction, is estimated to have Josephson critical current density jc of 19 kA/cm2. The Al/Py/Al/AlOx/Py/Al/Nb multilayer is deposited in a separate vacuum run after in situ ionmilling of about 8 nmof the top Nb layer. The devices are patterned using optical lithography and tested at 4.2 K. We have observed a small-signal current gain in the range of 5-9.We demonstrate that proper device engineering allows one to efficiently control the maximum Josephson current in the SISF acceptor junction using the quasiparticle injection.
AB - We report the results of a study of the current gain in high Josephson critical current density (jc ) superconductingferromagnetic transistors with the SISFIFS structure [where S, I, and F denote a superconductor (Nb), an insulator (AlOx), and a ferromagnetic material (permalloy, Py), respectively]. The Nb/AlOx/Nb trilayer, which serves as the acceptor (SIS) junction, is estimated to have Josephson critical current density jc of 19 kA/cm2. The Al/Py/Al/AlOx/Py/Al/Nb multilayer is deposited in a separate vacuum run after in situ ionmilling of about 8 nmof the top Nb layer. The devices are patterned using optical lithography and tested at 4.2 K. We have observed a small-signal current gain in the range of 5-9.We demonstrate that proper device engineering allows one to efficiently control the maximum Josephson current in the SISF acceptor junction using the quasiparticle injection.
KW - Josephson effect
KW - Superconducting-ferromagnetic hybrid structures
KW - proximity effect
KW - quasiparticle injection
KW - superconducting transistor
KW - superconductivity
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U2 - 10.1109/TASC.2016.2637864
DO - 10.1109/TASC.2016.2637864
M3 - Article
AN - SCOPUS:85014898244
VL - 27
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
SN - 1051-8223
IS - 4
M1 - 7779084
ER -