Long range statistical fluctuations of the crossed Josephson current

Abstract

We investigate the crossed Josephson effect in a geometry consisting of a double ferromagnetic bridge between two superconductors, with tunnel interfaces. The crossed Josephson current vanishes on average because the Andreev reflected hole does not follow the same sequence of impurities as the incoming electron. We show that i) the root mean square of the crossed Josephson current distribution is proportional to the square root of the junction area; and ii) the coherent coupling mediated by fluctuations is ``long range'' since it decays over the ferromagnet phase coherence length $l_{\varphi }$, larger than the exchange length. We predict a crossed Josephson current due to fluctuations if the length of the ferromagnets is smaller than $l_{\varphi }$ and larger than the exchange length ${\xi }_h$.

8 pages, 3 figures, modifications in the presentation

References in corpus (7)

• Evidence for crossed Andreev reflection in superconductor-ferromagnet hybrid structures
• Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction
• Current-current correlations in hybrid superconducting and normal metal multiterminal structures
• Sign of the crossed conductances at a FSF double interface
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Cited by in corpus (1)

• Non local Andreev reflection in a carbon nanotube superconducting quantum interference device