Josephson junction and Josephson device
AssigneeJapan Science and Technology Agency
InventorsAtsutaka Maeda, Espinoza Luis Beltran Gomez
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Abstract
A novel Josephson junction and a novel Josephson junction device are provided which eliminates the need to form an insulating barrier layer. The Josephson junction (1) comprises a superconductor layer (2) and a ferromagnetic layer (3) formed on a middle part (2C) of the superconductor layer (2). The ferromagnetic layer (3) may consist of an electrically conductive or insulating ferromagnetic layer, and may be an electrically conductive ferromagnetic layer formed via an insulating layer. With the superconductor layer (2) formed of a high temperature superconductor, a Josephson junction (1) is provided having large IcRN product. The Josephson junction (1) can be used as a junction for a variety of Josephson devices.
Claims19
A Josephson junction comprising:
- a substrate;
- a high temperature superconductor layer having a crystal structure formed on said substrate;
- and
- a ferromagnetic layer formed on a middle part of said high temperature superconductor layer,
- wherein a width of said high temperature superconductor layer at the middle part is less than a Josephson penetration length, and the ferromagnetic layer is transforming at least a portion of the high temperature superconductor layer at the middle part thereof to insulator so as to form a Josephson junction.
A Josephson junction comprising:
- a substrate;
- a high temperature superconductor layer having a crystal structure formed on said substrate;
- and
- a ferromagnetic layer formed on a middle part of said high temperature superconductor layer,
- wherein a width of at least part of said middle part of said high temperature superconductor layer is narrower than a width of both sides of said high temperature superconductor layer serving as electrodes, and
- wherein the width of said at least part of the middle part of said high temperature superconductor layer is less than a Josephson penetration length, and the ferromagnetic layer is transforming at least a portion of the high temperature superconductor layer at the middle part thereof to insulator so as to form a Josephson junction.
Dependencies are inferred from the claim text.