High gain josephson device

Claim 2

A high gain Josephson device comprising: first and second superconducting electrodes, a tunnel barrier between said electrodes through which DC zero voltage Josephson tunneling currents can pass, current mEans connected to at least one of said electrodes for providing Josephson current to said device, gain means for providing a magnetic field through said tunnel barrier which is instantaneously proportional to the magnitude of said zero voltage Josephson current through said barrier.

Claim 3

The device of claim 1, where said gain means includes means for adjusting the proportionality between said magnetic field and said Josephson current.

Claim 4

The device of claim 1, where said gain means a conductor adjacent said Josephson device and insulated therefrom having a current flowing therein which is instantaneously proportional to the magnitude of said Josephson current.

Claim 5

The device of claim 3, where said conductor is connected to said current means which provides said Josephson current to said device.

Claim 6

The device of claim 3, further including at least one further conductor adjacent said Josephson device, current flow through said further conductor creating a magnetic field intercepting said Josephson device for controlling the amount of maximum Josephson current which can pass through said device.

Claim 7

The device of claim 1, where said gain means includes a feedback conductor connected to one of said electrodes for returning a current proportional to said Josephson current in a path adjacent said device, said proportional current producing a magnetic field intercepting said device.

Claim 8

The device of claim 6, where said feedback conductor is comprised of the same superconductive material as the electrode to which it is connected.

Claim 9

A high gain Josephson device comprising: a Josephson tunnel junction comprised of: a first superconducting electrode for receiving DC zero voltage Josephson tunneling current from a current source, a second superconducting electrode for carrying said Josephson current, a tunnel barrier separating said first and second electrodes, said barrier supporting the flow of said zero voltage Josephson current therethrough, a current source for applying said Josephson current to said first electrode, conducting means electrically connected to only one of said electrodes for carrying current proportional to said zero voltage Josephson tunneling current for producing a magnetic field in said junction which is instantaneously proportional to said zero voltage Josephson current at all instants of time.

Claim 10

A high gain Josephson device comprising: a Josephson tunnel junction comprised of: a first superconducting electrode for receiving DC zero voltage Josephson tunneling current from a current source, a second superconducting electrode for carrying said Josephson current, a tunnel barrier separating said first and second electrodes, said barrier supporting the flow of said zero voltage Josephson current therethrough, a current source for applying said Josephson current to said first electrode, conducting means electrically connected to only one of said electrodes for carrying current proportional to said zero voltage Josephson tunneling current for producing a magnetic field in said junction which is instantaneously proportional to said zero voltage Josephson current at all instants of time.

Claim 11

The device of claim 8, where said means is an electrically parallel network of conductors whose self-inductance determines the magnitude of said proportional current which establishes said proportional magnetic field intercepting said junction.

Claim 12

The device of claim 8, further including a second conductor insulated from said Josephson device having a bias current therein which produces a bias magnetic field in said junction, and a third conductor insulated from said Josephson device having control current therein which establishes a control magnetic field in said junction, said control current being adjustable in magnitude, a second current source for providing bias current to sais second conductor, and a third current source for providing said control current to said third conductor.

Claim 13

The device of claim 8, further including a superconducting ground plane insulated from said Josephson junction.

Claim 14

The device of claim 8, wherein said superconducting means feeds back said Josephson current in a conductor which passes adjacent said junction and is insulated therefrom.

Claim 15

A high gain Josephson device, comprising: a superconductive ground plane, a first superconducting electrode insulated from said ground plane, a second superconductive electrode, a tunnel barrier located between said first and second superconductive electrodes, said tunnel barrier being able to support DC zero voltage Josephson tunneling current therethrough, current means connected to said first and second electrodes for providing sAid Josephson tunneling current through said tunnel barrier, a first conductor located adjacent said second electrode, said first conductor carrying a first current therein which is always instantaneously proportional to said zero voltage Josephson current, said first current producing a first magnetic field which couples to said Josephson device, a second conductor located adjacent said second electrode for carrying a second current therein whose magnitude is variable, said second current producing a second magnetic field which couples to said Josephson device, a second current source connected to said second conductor for providing said second currents therein.

Claim 16

A high gain Josephson device, comprising: a superconductive ground plane, a first superconducting electrode insulated from said ground plane, a second superconductive electrode, a tunnel barrier located between said first and second superconductive electrodes, said tunnel barrier being able to support DC zero voltage Josephson tunneling current therethrough, current means connected to said first and second electrodes for providing sAid Josephson tunneling current through said tunnel barrier, a first conductor located adjacent said second electrode, said first conductor carrying a first current therein which is always instantaneously proportional to said zero voltage Josephson current, said first current producing a first magnetic field which couples to said Josephson device, a second conductor located adjacent said second electrode for carrying a second current therein whose magnitude is variable, said second current producing a second magnetic field which couples to said Josephson device, a second current source connected to said second conductor for providing said second currents therein.

Claim 17

The device of claim 13, where said first conductor is electrically connected to only one of said superconducting electrodes.

Claim 18

The device of claim 14, where said first conductor is a single branch in a parallel network of conductors electrically connecting said first conductor to one of said electrodes, wherein each branch of said parallel network has different self-inductance.

Claim 19

The device of claim 13, where said first conductor is connected to a first current source which provides current that is always instantaneously proportional to said zero voltage Josephson tunneling current through said device.

Claim 20

The device of claim 16, where said first current source is comprised of said Josephson device.

Claim 21

The device of claim 16, where said first current source is comprised of said current means connected to said first and second electrodes.

Claim 22

The device of claim 13, including at least one further conductor located adjacent said second electrode and insulated therefrom having current therein which creates a magnetic field in said tunnel barrier.