METHOD FOR READING OUT MAGNETIC FIELDS WITH A <i>DC</i> SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE (<i>DC</i>-SQUID) AND CORRESPONDING DEVICE

摘要

ID (A) with a parallel-connected coupling transformer (B) comprises a step, wherein a non-constant ac bias current (Ib) is supplied. Said suppl ied non-constant ac bias current compensate s the current (Ic) induced by the transformer in such a way that the current flowing through the SQUID has a periodic rectangular function. This makes it possible to advantageously achieve low-noise operation of up to high reversal frequencies of over 100 kHz.