Title :
Effects of magnetic fields and microwave irradiation on step-edge and bi-epitaxial YBa/sub 2/Cu/sub 3/O/sub y/ SQUIDs
Author :
Horng, H.E. ; Lu, J.H. ; Wu, J.M. ; Yang, S.Y. ; Yang, H.C. ; Chern, J.D.
Author_Institution :
Dept. of Phys., Nat. Taiwan Normal Univ., Taipei, Taiwan
fDate :
6/1/1997 12:00:00 AM
Abstract :
Current-voltage (I-V) curves of step-edge YBa/sub 2/Cu/sub 3/O/sub y/ junctions, SQUIDs, and Junctions in parallel in a magnetic field and under microwave irradiation were measured. I/sub c/-/spl Phi/ curves for a single Josephson junctions show Fraunhofer diffraction pattern. The voltage of SQUIDs and Josephson junctions in parallel at a constant bias current is modulated by external magnetic fields. In additional to integer Shapiro steps, non-integer constant-voltage steps were observed under microwave irradiation in bi-epitaxial SQUIDs. The non-integer voltage steps can be modulated by the microwave power and the applied magnetic field.
Keywords :
Fraunhofer diffraction; Josephson effect; SQUIDs; barium compounds; high-temperature superconductors; superconducting epitaxial layers; yttrium compounds; Fraunhofer diffraction; Josephson junction; Shapiro steps; YBa/sub 2/Cu/sub 3/O; YBa/sub 2/Cu/sub 3/O/sub y/; bi-epitaxial SQUID; constant-voltage steps; current-voltage characteristics; magnetic field; microwave irradiation; step-edge SQUID; Critical current; Diffraction; Gaussian processes; Magnetic field measurement; Magnetic fields; Magnetic flux; Magnetic modulators; SQUIDs; Voltage; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
