J.Z. Sun, L.S. Yu-Jahnes, et al.
IEEE TAS
Measurements of TlBaCaCuO-based dc superconducting quantum interference devices (SQUIDs) performed using a practical feedback circuit gave a flat frequency response and an energy sensitivity of 6×10-30 J/Hz at 5 kHz and 77 K with an 80 pH SQUID. Flux-locked loop operation was demonstrated to be strongly effective in eliminating the magnetic field hysteresis of the SQUID. The SQUIDs were operated in the flux-locked loop at temperatures over 90 K and the 1/f noise was found to decrease with increasing temperature near 77 K.
J.Z. Sun, L.S. Yu-Jahnes, et al.
IEEE TAS
M.W. Shafer, T. Penney, et al.
Physical Review B
R.B. Laibowitz, R.H. Koch, et al.
High Temperature Superconducting Compounds 1990
V. Foglietti, R.H. Koch, et al.
Journal of Applied Physics