Linewidth of Josephson oscillations in YBa/sub 2/Cu/sub 3/O/sub 7-x/ grain-boundary junctions

Author

Divin, Y.Y. ; Mygind, J. ; Pedersen, N.F. ; Chaudhari, P.

Author_Institution

Tech. Univ. of Denmark, Lyngby, Denmark

Volume

3

Issue

1

fYear

1993

fDate

3/1/1993 12:00:00 AM

Firstpage

2337

Lastpage

2340

Abstract

The AC Josephson effect in YBa/sub 2/Cu/sub 3/O/sub 7-x/ grain-boundary junctions (GBJs) was studied in the temperature range from 4 K to 90 K. The temperature dependence of the linewidth of millimeter-wave Josephson oscillations was measured, and it is shown that the derived effective noise temperature of GBJ might be as low as the physical temperature in the temperature range investigated. This makes it possible to use the resistively shunted junction (RSJ) model with thermal fluctuations to get a limiting performance of high-T/sub c/ devices utilizing the AC Josephson effect. The lowest value of the linewidth of 72 GHz Josephson oscillations observed at 77 K was equal to 380 MHz, which demonstrates the applicability of GBJ, particularly in the field of radiation spectroscopy, even at liquid nitrogen temperatures.<>

Keywords

Josephson effect; barium compounds; fluctuations in superconductors; grain boundaries; high-frequency effects; high-temperature superconductors; spectral line breadth; superconducting junction devices; yttrium compounds; 4 to 90 K; 72 GHz; 77 K; AC Josephson effect; Josephson oscillation linewidth; RSJ model; YBa/sub 2/Cu/sub 3/O/sub 7-x/ grain boundary junctions; effective noise temperature; high temperature effect; liquid N/sub 2/ temperature; millimeter wave oscillations; radiation spectroscopy; resistively shunted junction model; temperature dependence; thermal fluctuations; Circuit analysis; Coupling circuits; Critical current; Frequency estimation; Impedance measurement; Josephson effect; Josephson junctions; Nitrogen; Temperature sensors; Voltage fluctuations;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/77.233433

Filename

233433