we have carried out extensive mappings of the dc characteristics and flux noise of an integrated, dc superconducting quantum interference device magnetometer as functions of bias current and applied flux. The open-loop white flux noise at 1 kHz measured without flux modulation [formula omitted] throughout a broad region of operation where the current-voltage and voltage-flux characteristics are smooth. The corresponding flux density noise [formula omitted]. We have also used a recent model of the coupled dc SQUID to calculate the frequency-dependent impedance Z(f) seen by the Josephson junctions. The peaks observed in Z(f) are shown to be consistent with features in the current-voltage characteristics at high bias currents.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering