%0 Journal Article
%A Faley, M. I.
%A Reith, P.
%A Stolyarov, V. S.
%A Golovchanskiy, I. A.
%A Golubov, A. A.
%A Hilgenkamp, H.
%A Dunin-Borkowski, R. E.
%T π-Loops With ds Josephson Junctions
%J IEEE transactions on applied superconductivity
%V 29
%N 5
%@ 1051-8223
%C New York, NY
%I IEEE
%M FZJ-2019-01195
%P 1 - 5
%D 2019
%X We fabricated Josephson junctions (JJs) between the d-wave superconductor (SC) YBa 2 Cu 3 O 7 -x (YBCO) and the s-wave SC Nb (ds-JJs) on graphoepitaxially buffered MgO substrates, studied ds-JJs at temperatures down to 30 mK and employed these JJs in π-loops. Current-voltage characteristics of ds-JJs oriented along the [100] axis of YBCO exhibited up to a factor of 200 higher critical current densities than ds-JJs oriented along the [110] axis of YBCO. The critical current Ic and the IcRn product of [100]-oriented 3 μm wide ds-JJs are ∼70 μA and ∼200 μV, respectively, at 4.2 K. Rectangular arrays of up to 40 000 π-loops based on such ds-JJs were investigated using a low temperature scanning superconducting quantum interference device (SQUID) microscope. We observed ordering of spontaneously generated half integer magnetic flux quanta in the π-loops correlated with minute spurious background magnetic fields, as well as with configurations and mutual coupling of the π-loops. We manipulated the magnetic states of the π-loops by the local application of magnetic fields using nearby planar coils. This paper paves the way for the use of π-loops in computations that are based on annealing processes.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000457591700001
%R 10.1109/TASC.2019.2892078
%U https://juser.fz-juelich.de/record/860441