Supercurrent density correlation function of YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// grain boundary Josephson junctions

Author

Froehlich, O.M. ; Schulze, H. ; Beck, A. ; Gerdemann, R. ; Mayer, B. ; Gross, R. ; Huebener, R.P.

Author_Institution

Phys. Inst., Tubingen Univ., Germany

Volume

5

Issue

2

fYear

1995

fDate

6/1/1995 12:00:00 AM

Firstpage

2188

Lastpage

2191

Abstract

We have measured the thermal noise induced slope R/sub p/(B) of the current-voltage characteristics of YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// Grain Boundary Josephson Junctions (GBJs) for I/spl rarr/0 in magnetic fields up to B=12 T. From the measured R/sub p/(B) dependences the magnetic field dependence of the critical current I/sub c/(B) was derived in the large magnetic field range between 0 and 12 T. Finally, the supercurrent density correlation function was obtained from the I/sub c/(B) dependence using the Wiener-Khinchine relation. By introducing the concept of the bright (BGCF) and dark ground correlation function (DGCF) a spatial filtering of the information on the supercurrent density distribution was obtained. The investigation of the BGCFs and the comparison to DGCFs gives clear evidence that supercurrent density has strong inhomogeneities on small length scales in the nanometer regime.<>

Keywords

Josephson effect; barium compounds; critical current density (superconductivity); grain boundaries; high-temperature superconductors; superconducting device noise; superconducting device testing; thermal noise; yttrium compounds; 0 to 12 T; Wiener-Khinchine relation; YBa/sub 2/Cu/sub 3/O/sub 7/; bright ground correlation function; critical current; current-voltage characteristics; dark ground correlation function; grain boundary Josephson junctions; supercurrent density correlation function; thermal noise induced slope; Critical current; Current measurement; Current-voltage characteristics; Density measurement; Grain boundaries; Information filtering; Josephson junctions; Magnetic field measurement; Magnetic noise; Noise measurement;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.403018

Filename

403018