Title :
Low-frequency noise of YBCO/Au junctions
Author :
Xu, Y. ; Ekin, J.W. ; Clickner, C.C.
Author_Institution :
Nat. Inst. of Stand. & Technol., Boulder, CO, USA
fDate :
6/1/1999 12:00:00 AM
Abstract :
We have fabricated ex-situ c-axis YBCO/Au junctions with low contact resistivities. These devices exhibit large low-frequency resistance fluctuations. At room temperature the junction noise spectrum is 1/f like. At liquid nitrogen temperature (77 K) and lower, the noise spectrum depends sensitively on the bias current, with certain bias levels producing clear two-level fluctuation behavior. The normalized resistance noise for these junctions at temperatures below 77 K has an average value of 2 to 3/spl times/10/sup -5/(Hz)/sup -1/2/. We discuss practical issues related to junction noise properties.
Keywords :
1/f noise; Josephson effect; barium compounds; contact resistance; gold; high-temperature superconductors; yttrium compounds; 1/f noise; 77 K; YBCO/Au Josephson junction; YBaCuO-Au; contact resistivity; low-frequency noise; resistance fluctuations; resistance noise; two-level system; Annealing; Conductivity; Contact resistance; Gold; High temperature superconductors; Low-frequency noise; Preamplifiers; Superconducting device noise; Temperature sensors; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
