Transport and interface properties in ramp-type Josephson junctions with a graded Y1−xPrxBa2Cu3Oy barrier

A unique feature of this novel barrier structure is that the effective thickness of the barrier can be varied even after fabrication, depending on the measuring temperature and the Pr-concentration gradient. It could make the transport process and the Josephson coupling differ from that of the conventional junctions. The temperature dependences of the barrier thickness and Josephson properties were investigated and compared with those of junctions with a conventional single barrier. Low values of proximity effect parameters found in our junctions show an advantage of this barrier structure.