Dresden 2014 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 30: Superconductivity - Poster Session

TT 30.1: Poster

Monday, March 31, 2014, 15:00–19:00, P2

Sample size dependence of the Josephson behavior of the interfaces in pyrolytic graphite — Ana Ballestar and •Pablo Esquinazi — Division of Superconductivity and Magnetism, University of Leipzig, Leipzig, Germany

Transport properties of TEM lamella graphite samples with embedded interfaces show evidence for granular superconductivity at elevated temperatures [1]. We show that the observed transition temperature decreases linearly with the sample/interface width, and finally vanishes for width size below 200 nm. We discuss the possible origin for this size dependence in terms of weak localization in two dimensions as found in superconducting/normal multilayers [2]. Our results clarify the different temperature dependence of the resistance in bulk pyrolytic graphite samples as well as the difference in the temperature region where a Josephson critical behavior is measured in graphite TEM lamellae.
A. Ballestar et al., New Journal of Phys., 15, 023024 (2013)
J. Guimpel et al., J Low Temp Phys 63, 151 (1986)