Title :
Coherent phase locking of high-Tc YBa2Cu3Oy Josephson junctions
Author :
Yang, H.C. ; Wu, C.H. ; Chen, M.J. ; Chen, J.H. ; Chen, C.H. ; Yu, H.W. ; Jeng, J.T. ; Horng, H.E.
Author_Institution :
Dept. of Phys., Nat. Taiwan Univ., Taipei, Taiwan
fDate :
3/1/2001 12:00:00 AM
Abstract :
We measured I-V curves and noise characteristics of high-Tc YBa2Cu3Oy step-edge Josephson junctions and serial junction arrays under microwave irradiation. The junctions were fabricated on step-edge MgO(100) substrates with low step angles (~30°). The junction array shows the resistively shunted junction (RSJ) behavior for at least 50 junctions and reveals a coherent phase locking under microwave irradiation. The variation of Ic was 16% for a 150-junctions array distributed along the step-edge line of 1.5 mm in width. The voltage noise, Sv, of the serial junction array scales as the number of junctions, N. The value of SIR, (SIR=|(δIc/Ic )||(δR/R)|), for a single and 50-junctions obtained from the fluctuation measurement is consistent with the result derived from IcRn∝(Jc)q, with q=0.5
Keywords :
Josephson effect; barium compounds; fluctuations in superconductors; high-temperature superconductors; superconducting arrays; yttrium compounds; MgO(100) substrate; YBa2Cu3O; YBa2Cu3Oy step-edge Josephson junction; coherent phase locking; current-voltage characteristics; high-Tc superconductor; microwave irradiation; resistively shunted junction; serial junction array; voltage noise; Atomic force microscopy; Grain boundaries; Josephson junctions; Microwave antenna arrays; Microwave measurements; Noise measurement; Phased arrays; Substrates; Surface morphology; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
