Title :
Relaxation oscillation SQUIDs with high delta V/ delta Phi
Author :
Adelerhof, D.J. ; Nijstad, H. ; Flokstra, J. ; Rogalla, H.
Author_Institution :
Dept. of Appl. Phys., Twente Univ., Enschede, Netherlands
fDate :
3/1/1993 12:00:00 AM
Abstract :
Relaxation oscillation SQUIDs (ROSs) based on Nb/Al, AlO/sub x//Al/Nb Josephson tunnel junctions have been designed and fabricated. The hysteretic SQUIDs (superconducting quantum interference devices) have a maximum critical current of about 130 mu A and an inductance of 20 pH. A voltage modulation of 40 mu V and a flux to voltage transfer delta V/ delta Phi of 4 MV/ Phi /sub 0/ have been measured in these SQUIDs. Double relaxation oscillation SQUIDs (DROSs), which are based on two hysteretic SQUIDs, showed transfer coefficients up to 77 mV/ Phi /sub 0/. The intrinsic white flux noise of the DROSs is smaller than 3-5 mu Phi /sub 0// square root Hz. It is noted that the results are very promising for a next generation of SQUID systems with simplified read-out.<>
Keywords :
SQUIDs; aluminium; aluminium compounds; critical currents; electron device noise; niobium; relaxation oscillators; white noise; 130 muA; DROS; I-V characteristics; Josephson tunnel junctions; Nb-Al-AlO/sub x/-Al-Nb; flux to voltage transfer; hysteretic SQUIDs; inductance; intrinsic white flux noise; maximum critical current; relaxation oscillation SQUIDs; voltage modulation; Critical current; Delta modulation; Hysteresis; Inductance; Interference; Josephson junctions; Niobium; SQUIDs; Superconducting devices; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
