Evidence for Nonlocal Electrodynamics in Planar Josephson Junctions
2013 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 111, no 11, 117002Article in journal (Refereed) Published
We study the temperature dependence of the critical current modulation I-c(H) for two types of planar Josephson junctions: a low-T-c Nb/CuNi/Nb and a high-T-c YBa2Cu3O7-delta bicrystal grain-boundary junction. At low T both junctions exhibit a conventional behavior, described by the local sine-Gordon equation. However, at elevated T the behavior becomes qualitatively different: the I-c(H) modulation field Delta H becomes almost T independent and neither Delta H nor the critical field for the penetration of Josephson vortices vanish at T-c. Such an unusual behavior is in good agreement with theoretical predictions for junctions with nonlocal electrodynamics. We extract absolute values of the London penetration depth lambda from our data and show that a crossover from local to nonlocal electrodynamics occurs with increasing T when lambda(T) becomes larger than the electrode thickness.
Place, publisher, year, edition, pages
2013. Vol. 111, no 11, 117002
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-94861DOI: 10.1103/PhysRevLett.111.117002ISI: 000324308800015OAI: oai:DiVA.org:su-94861DiVA: diva2:656795