Title :
Current phase relation of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/(-/spl delta/) step edge junction
Author :
Polushkin, V. ; Uchaikin, S. ; Knappe, S. ; Koch, H. ; David, B. ; Grundler, D.
Author_Institution :
Physikalisch Tech. Bundesanstalt, Berlin, Germany
fDate :
6/1/1995 12:00:00 AM
Abstract :
The small signal rf impedance of Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta// step edge junction rf SQUIDs operating in a strongly nonhysteretic mode has been measured. The phase dependent inductance L/sub J/(/spl phi/) and the current phase relation I/sub p/(/spl phi/) of step-edge junctions embedded in SQUIDs are calculated from measurement data following the Vincent-Deaver approach. Two of three junctions investigated revealed a sinusoidal current phase relation. I/sub p/(/spl phi/) of the third junction seemed to be non-sinusoidal and hysteretic. A model explaining the origin of the non-sinusoidality of I/sub p/(/spl phi/) is proposed.<>
Keywords :
Cooper pairs; Josephson effect; SQUIDs; barium compounds; electric impedance; high-temperature superconductors; inductance; superconducting device testing; yttrium compounds; Josephson junction model; Vincent-Deaver approach; Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-/spl delta// step edge junction; Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7/; flux-to-voltage curve; nonsinusoidal hysteretic current phase relation; phase dependent inductance; sinusoidal current phase relation; small signal RF impedance; step edge junction RF SQUIDs; strongly nonhysteretic mode; Circuit noise; Coupling circuits; Inductance; Josephson junctions; Magnetic flux; Noise measurement; Preamplifiers; SQUIDs; Superconducting device noise; Temperature distribution;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
