A high-T/sub c/ Josephson junction on a narrow tungsten line formed by focused ion beam-chemical vapor deposition [of NdBaCuO]

We have fabricated two types of high-T/sub c/ Josephson junctions using a focused ion beam technique. High-T/sub c/ junctions fabricated using a narrow-focused Ga-ion beam to damage a substrate, resulting in a geometrical defect prior to high-T/sub c/ layer deposition, show flux flow-like characteristics for the SrTiO/sub 3/ substrate. The current-voltage characteristics of the junctions which are fabricated on a narrow tungsten (W) metal layer deposited on both MgO and SrTiO/sub 3/ substrates using a focused ion beam chemical vapor deposition technique are qualitatively consistent with a resistively shunted junction model and show Shapiro steps under microwave irradiation.