Josephson Effects in Niobium Variable-Thickness Bridges

Oblique deposition and anodization technique have been used to fabricate niobium variable-thickness bridges of length ∼0.2 µm. Very sharp microwave-induced steps are observed and the height changes periodically as the microwave power increases. The bridges are found to show Josephson effects in a wide temperature range and have large I c R n products which are favorable in practical Josephson devices.