METHOD FOR READING OUT MAGNETIC FIELDS WITH A dc SUPERCONDUCTING QUANTUM INTERFERENCE DEVICE T( dc -SQUID) AND CORRESPONDING DEVICE

摘要

The inventive method for operating a dc SQUID (A) with a parallel-connected coupling transformer (B) comprises a step, wherein a non-constant ac bias current (Ib) is supplied. Said supplied non-constant ac bias current compensates 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.