Josephson junction device and method of manufacturing the same

A Josephson junction comprising:

• a planar substrate having a first superconducting electrode layered thereon and having a linear groove through the planar substrate and the first superconducting electrode, the linear groove having a left wall comprised of a left portion of the planar substrate and a left portion of the first superconducting electrode, the linear groove also having a right wall comprised of a right portion of the planar substrate and a right portion of the first superconducting electrode;
• a tunneling film comprising a left portion lining the left wall of the linear groove and comprising a right portion lining the right wall of the linear groove;
• a second superconducting electrode in the linear groove having a left end with a first contact area with the left portion of the tunneling film and having a right end with a second contact area with the right portion of the tunneling film, the second contact area larger than the first contact area.