TY  - JOUR
AU  - Faley, M. I.
AU  - Reith, P.
AU  - Satrya, C. D.
AU  - Stolyarov, V. S.
AU  - Folkers, B.
AU  - Golubov, A. A.
AU  - Hilgenkamp, H.
AU  - Dunin-Borkowski, R. E.
TI  - MoRe/YBCO Josephson junctions and π -loops
JO  - Superconductor science and technology
VL  - 33
IS  - 4
SN  - 0953-2048
CY  - Bristol
PB  - IOP Publ.
M1  - FZJ-2020-00511
SP  - 044005 -
PY  - 2020
AB  - We have developed Josephson junctions between the d-wave superconductor YBa2Cu3O7−x (YBCO) and the s-wave Mo0.6Re0.4 (MoRe) alloy superconductor (ds-JJs). Such ds Josephson junctions are of interest for superconducting electronics making use of incorporated π-phase shifts. The I(V)-characteristics of the ds-JJs demonstrate a twice larger critical current along the [100] axis of the YBCO film compared to similarly-oriented ds-JJs made with a Nb top electrode. The characteristic voltage I c R n of the YBCO–Au–MoRe ds-JJs is 750 μV at 4.2 K. The ds-JJs that are oriented along the [100] or [010] axes of the YBCO film exhibit a 200 times higher critical current than similar ds-JJs oriented along the [110] axis of the same YBCO film. A critical current density J c = 20 kA cm−2 at 4.2 K was achieved. Different layouts of π-loops based on the novel ds-JJs were arranged in various mutual coupling configurations. Spontaneous persistent currents in the π-loops were investigated using scanning SQUID microscopy. Magnetic states of the π-loops were manipulated by currents in integrated bias lines. Higher flux states up to ±2.5Φ0 were induced and stabilized in the π-loops. Crossover temperatures between thermally activated and quantum tunneling switching processes in the ds-JJs were estimated. The demonstrated ability to stabilise and manipulate states of π-loops paves the way towards new computing concepts such as quantum annealing computing.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000537735500002
DO  - DOI:10.1088/1361-6668/ab7053
UR  - https://juser.fz-juelich.de/record/873062
ER  -