Josephson contacts in high temperature superconductors and method of fabrication thereof

Method for fabricating high temperature superconductors, which, after the following fabrication steps, form at least one intrinsic Josephson junction:

• a small, single-crystal, the dimensions of which are below the penetration depth of the magnetic field perpendicular to the crystallographic c-axis, is drawn from a melt of a high temperature superconductor or deposited epitaxially on a substrate;
• the single-crystal is fabricated or post-processed in an inert atmosphere or in a vacuum at controlled oxygen partial pressure for modifying regions between superconducting layers, planes or double planes, of the small single-crystal;
• at the boundaries parallel to the superconducting layers of the small single-crystal, well conducting contacts are vapor deposited.

A monocrystalline high temperature superconductor plate, forming an intrinsic Josephson junction, having superconducting planes, arranged in layers, wherein the spacing of adjacent superconducting layers or double layers is roughly 10 times as large as the superconducting Ginzburg-Landau coherence length in the direction of this spacing, and wherein the monocrystalline plate, or the layers of the plate, have dimensions in the direction of the superconducting planes not larger than the penetration depth of an external magnetic field parallel to the planes, formed by a process comprising the steps of:

• a small single-crystal, the dimensions of which are below the penetration depth of the magnetic field perpendicular to the crystallographic c-axis, is drawn from a melt of a high temperature superconductor or deposited epitaxially on a substrate;
• the single-crystal is fabricated or post-processed in an inert atmosphere or in a vacuum at controlled oxygen partial pressure for modifying regions between superconducting layers, planes or double planes, of the small single-crystal;
• at the boundaries parallel to the superconducting layers of the small single-crystal, well conducting contacts are vapor deposited.