Half - h/2e - Oscillations of SQUIDs

ORAL

Abstract

The current-voltage-voltage characteristics of Superconducting Quantum Interference Devices (SQUIDs) are known to modulate as a function of applied magnetic filed with a period of one flux quantum $\Phi _{0}=h$/2e. Here we report on the fabrication and properties of SQUIDs modulating with a period of 1/2 x $\Phi _{0}$. The characteristics of these bicrystal SQUIDs are consistent with either a strong sin(2\textit{$\phi )$} component of the current-phase relation o f the Josephson current, or with an interaction between the Cooper-pairs, causing an admixture of quartets to the condensate.

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Authors

  • Jochen Mannhart

    • Institute of Physics, Augsburg University, Germany

  • Christof Schneider

  • German Hammerl

  • Gennadij Logvenov

  • Thilo Kopp

    • Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86135 Augsburg

  • John Kirtley

    • IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598, USA

  • Peter Hirschfeld

    • Department of Physics, University of Florida
    • Dept. of Physics, U. Florida
    • Department of Physics, University of Florida, Gainesville, FL32611-8440
    • Department of Physics, University of Florida, Gainesville, Florida 32611, USA

  • Hel\`ene Raffy

    • Laboratoire de Physique des Solides, Universit\`e de Paris-Sud, 91405 Orsay, France