Fringe field superconducting system

Claim 2

A switch, comprising: a pathway of a superconductive material; and a ferromagnet; wherein said ferromagnet is adapted for having at least a first magnetization state and a second magnetization state; wherein fringe fields from said ferromagnet in said first magnetization state do not exceed a predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state; wherein fringe fields from said ferromagnet in said second magnetization state exceed said predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state.

Claim 3

The switch of claim 1, wherein said superconductive pathway is a stripline.

Claim 4

The switch of claim 1, wherein said ferromagnet has at least two easy axes of magnetization, and wherein said first magnetization state corresponds to the magnetization of said ferromagnet in the direction of a first easy axis of magnetization, and said second magnetization state corresponds to the magnetization of said ferromagnet in the direction of a second easy axis of magnetization.

Claim 5

The switch of claim 1, wherein fringe fields from said ferromagnet in said second magnetization state establish a weak link in said superconductive pathway.

Claim 6

The switch of claim 1, wherein said switch further comprises one or more write wires for setting the magnetization state of said ferromagnet.

Claim 7

The switch of claim 5, wherein said one or more write wires comprise two or more write wires.

Claim 8

The switch of claim 5, wherein said one or more write wires comprise two or more write wires, wherein a first write wire is substantially parallel to said superconductive pathway, wherein said second write wire is substantially perpendicular to said superconductive pathway, wherein said first and second write wires are adapted for setting the magnetic state of said ferromagnet to said first and second magnetization states, respectively, with the application of a write pulse to said first or said second write wires, respectively, and wherein said ferromagnet is adapted for maintaining each of said first and second magnetization states upon the application and removal of said write pulses to said first and second write wires, respectively.

Claim 9

The switch of claim 7, wherein said two or more write wires are two or more intersecting write wires.

Claim 10

The switch of claim 7, wherein said two or more write wires are two write wires.

Claim 11

The switch of claim 5, wherein said ferromagnet has a single easy axis of magnetization corresponding to said first magnetization state, and wherein a write wire is adapted for setting the magnetization state of said ferromagnet to said second magnetization state, and wherein the ferromagnet is adapted for switching to said second magnetization state in the presence of a writing pulse in said write wire, and switching to said first magnetization state in the absence of writing pulse in said write wire.

Claim 12

The switch of claim 5, wherein said ferromagnet has a single easy axis of magnetization corresponding to said second magnetization state, and wherein a write wire is adapted for setting the magnetization state of said ferromagnet to said first magnetization state, and wherein the ferromagnet is adapted for switching to said first magnetization state in the presence of a writing pulse in said write wire, and switching to said second magnetization state in the absence of writing pulse in said write wire.

Claim 13

The switch of claim 1, wherein said ferromagnet is adapted for having a continuous range of magnetization states, each of said range of magnetization states establishing a magnetic fringe field in said superconductive pathway, wherein said fringe fields have a continuous range, wherein said fringe fields suppress superconductivity in said superconductive pathway over a continuous range, thereby providing a tunable Josephson junction.

Claim 18

A superconducting non-volatile memory element, comprising: a pathway of a superconductive material; a ferromagnet, wherein said ferromagnet is adapted for having at least a first magnetization state and a second magnetization state, wherein fringe fields from said ferromagnet in said first magnetization state do not exceed a predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein fringe fields from said ferromagnet in said second magnetization state exceed said predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein said ferromagnet is adapted for retaining magnetization states after the application and removal of a write pulse through a write wire; a first write wire, adapted for setting said ferromagnet in said first magnetization state; a second write wire, adapted for setting said ferromagnet in said second magnetization state; and a voltage detector, for reading a voltage across said superconductive pathway.

Claim 19

A superconducting non-volatile memory element, comprising: a pathway of a superconductive material; a ferromagnet, wherein said ferromagnet is adapted for having at least a first magnetization state and a second magnetization state, wherein fringe fields from said ferromagnet in said first magnetization state do not exceed a predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein fringe fields from said ferromagnet in said second magnetization state exceed said predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein said ferromagnet is adapted for retaining magnetization states after the application and removal of a write pulse through a write wire; a first write wire, adapted for setting said ferromagnet in said first magnetization state; a second write wire, adapted for setting said ferromagnet in said second magnetization state; and a voltage detector, for reading a voltage across said superconductive pathway.

Claim 20

A superconducting voltage amplifier, comprising: a pathway of a superconductive material; a ferromagnet, wherein said ferromagnet is adapted for having at least a first magnetization state and a second magnetization state, wherein fringe fields from said ferromagnet in said first magnetization state do not exceed a predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein fringe fields from said ferromagnet in said second magnetization state exceed said predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein said ferromagnet is adapted for switching from said first magnetization state to said second magnetization state upon the application of a write pulse, and is further adapted for reverting to said first magnetization state upon the removal of said write pulse; a write wire, adapted for applying a write pulse for setting said ferromagnet in said second magnetization state, thereby switching the state of said superconductive pathway from superconducting to at least partially normal; and a voltage detector, for reading a voltage across said superconductive pathway.

Claim 21

A superconducting voltage amplifier, comprising: a pathway of a superconductive material; a ferromagnet, wherein said ferromagnet is adapted for having at least a first magnetization state and a second magnetization state, wherein fringe fields from said ferromagnet in said first magnetization state do not exceed a predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein fringe fields from said ferromagnet in said second magnetization state exceed said predetermined magnetic field in said superconductive pathway to convert at least a portion of said superconductive pathway to the normal state, wherein said ferromagnet is adapted for switching from said first magnetization state to said second magnetization state upon the application of a write pulse, and is further adapted for reverting to said first magnetization state upon the removal of said write pulse; a write wire, adapted for applying a write pulse for setting said ferromagnet in said second magnetization state, thereby switching the state of said superconductive pathway from superconducting to at least partially normal; and a voltage detector, for reading a voltage across said superconductive pathway.

Claim 22

A switch, comprising: means for superconductively carrying a current; means for applying at least a first and a second magnetic field state to said superconductor means; wherein fringe fields from said magnetic field state means in said first magnetic field state do not exceed a predetermined magnetic field in said superconductor means to convert at least a portion of said superconductor means to the normal state; and wherein fringe fields from said magnetic field state means in said second first magnetic field state exceed said predetermined magnetic field in said superconductor means to convert at least a portion of said superconductor means to the normal state.

Claim 23

A switch, comprising: means for superconductively carrying a current; means for applying at least a first and a second magnetic field state to said superconductor means; wherein fringe fields from said magnetic field state means in said first magnetic field state do not exceed a predetermined magnetic field in said superconductor means to convert at least a portion of said superconductor means to the normal state; and wherein fringe fields from said magnetic field state means in said second first magnetic field state exceed said predetermined magnetic field in said superconductor means to convert at least a portion of said superconductor means to the normal state.

Claim 26

The method of claim 18, wherein said first voltage state corresponds to a finite voltage across said superconductive pathway, and wherein said second voltage state corresponds to an essentially zero voltage across said superconductive pathway.

Claim 27

The switch of claim 1, wherein said pathway of a superconductive material is a single pathway of a superconductive material.

Claim 28

The switch of claim 20, wherein said single pathway of a superconductive material is a monolithic pathway of a superconductive material.

Claim 29

The switch of claim 1, wherein a single surface of said ferromagnet faces said pathway of a superconductive material.

Claim 30

The switch of claim 1, wherein said ferromagnet overhangs said pathway of a superconductive material along an axis.

Claim 31

The switch of claim 1, further comprising an insulating layer interposed between said pathway of a superconductive material and said ferromagnet, for suppressing the proximity effect in said pathway of a superconductive material.

Claim 32

The switch of claim 24, wherein said insulating layer has an angstrom-scale thickness.

Claim 33

The method of claim 14, wherein said step of changing said magnetization state of said ferromagnet from said second magnetization state to said first magnetization state returns said portion of said superconductive pathway to said superconductive state without hysteresis in said superconductive pathway.