Observation of superconducting device using magnetic imaging system with amicro-DC superconducting quantum interference device magnetometer

A magnetic imaging system with a micro-DC superconducting quantum interfere nce device magnetometer has been developed to evaluate superconducting film s and to inspect a superconducting device with a high spatial resolution. A superconducting device, i.e., a DC-SQUID made of a superconducting Nb thin film, was observed using the system. The shape of the device was identifie d by applying the Meissner effect. The trapped fluxes in the device were cl early visible. In addition, the input current and the shielding current flo wing on the device were detected by feeding a current to the device. It was confirmed experimentally that the magnetic imaging system was effective in studying superconducting devices.