SQUID
Videos
A SQUID is a very sensitive magnetometer used to measure extremely weak magnetic fields, based on superconducting loops containing Josephson junctions.
Sensing element of a SQUID, 2008
A prototype SQUID
The inner workings of an early SQUID, circa 1990
SERF
Videos
A spin exchange relaxation-free magnetometer is a type of magnetometer developed at Princeton University in the early 2000s. SERF magnetometers measure magnetic fields by using lasers to detect the in
SQUID
…comparison, a typical refrigerator magnet produces 10−2 T, and some processes in animals produce very small magnetic fields between 10−9 T and 10−6 T. SERF atomic magnetometers, invented in the early 2000s are potentially more sensitive and do not require cryogenic refrigeration but are orders of magnitude…
SERF components mockup