Superconduting device having an extremely short superconducting channel formed of oxide superconductor material and method for manufacturing the same

A superconducting device which controls current flow within a superconducting channel thereof in accordance with a gate voltage applied to a gate electrode region of said device, said device comprising:

• a substrate,
• a first oxide superconductor thin film situated at an angle with respect to a deposition surface of said substrate, said first oxide superconductor thin film having a thickness of not greater than 5 nm and defining said superconducting channel,
• a superconductor source electrode region and a superconductor drain electrode region formed at opposite ends of said superconducting channel, so that a superconducting current can flow through said superconducting channel between said superconductor source electrode region and said superconductor drain electrode region,
• a second oxide superconductor thin film situated parallel to said deposition surface of said substrate, the second oxide superconductor thin film defining said gate electrode region, and
• a first insulating layer which separates said superconducting channel and said gate electrode region and which prevents tunnel current therebetween,
• said gate electrode region having an end portion which abuts said first insulating layer, said gate voltage being applied to said gate electrode region such that an electric field produced by said gate voltage forms a depletion region within said superconducting channel without forming a Josephson junction.