Properties of YBaCuO nanobridges and dc-SQUIDs

YBaCuO nanobridges and inductively shunted dc-SQUIDs have been patterned by direct Focused Ion Beam milling. Nanobridges manifest true Josephson effect, which can be explained by coherent motion of Abrikosov vortices in the bridge. An enhancement of this effect is proposed to be due to local suppression of the superconducting properties within the nanobridge area. This leads to a transition from SNS to SS'S type behavior of the nanobridge with decreasing temperature. Temperature dependence of the critical current, dynamic resistance, and SQUID voltage-flux modulation is discussed. The flux noise level of the nanoSQUID is measured to be about 6.5 /spl mu//spl Phi//sub 0///spl radic/Hz at 62.7 K.