R.H. Koch, J.R. Rozen, et al.
Physical Review B - CMMP
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.
R.H. Koch, J.R. Rozen, et al.
Physical Review B - CMMP
A.H. Verbruggen, H. Stoll, et al.
Applied Physics A Solids and Surfaces
R.H. Koch, R.B. Laibowitz, et al.
Physical Review B
W.J. Gallagher, T. Worthington, et al.
Physica B+C