Magnetometer is a sensor for detection magnetic signals. To achieve a high-sensitivity in sensing weak magnetic signals, MagQu utilizes high-Tc superconducting quantum interference devices (SQUIDs)­ for high-sensitivity magnetometer.

SQUID is composed with two Josephson junctions in parallel. The output voltage cross Josephson junctions varies with magnetic flux through the loop formed with Josephson junctions in parallel. It is worthy noting that the limit of detection in magnetic field strength can be down to 1 pT. Thus, SQUID is usually useful to probing ultra-weak magnetic signal, and shows impacts to such applications as biomagnetic detections (e.g. magnetocardiography), non-destructive evaluation, geophysical investigation, low-field nuclei magnetic resonance, and magnetically labeled biomolecule assays.

MagQu is issuing high-Tc SQUID magnetometer: SQIMA3. Josephson junctions are such type as step-edge boundary (step-edge STO substrate). Features of SQIMA3 are listed as follows.