Magnetic flux source system

Patent metadata

Field	Value
Publication number	US-10989767-B2
Application number	US-202017065373-A
Country	US
Kind code	B2
Filing date	Oct 7, 2020
Priority date	Jun 26, 2018
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

One example includes a tunable current element. The element includes a first magnetic flux component that is configured to exhibit a bias flux in response to a first control current. The bias flux can decrease relative energy barriers between discrete energy states of the tunable current element. The element also includes a second magnetic flux component that is configured to exhibit a control flux in response to a second control current. The control flux can change a potential energy of the discrete energy states of the tunable current element to set an energy state of the tunable current element to one of the discrete energy states, such that the magnetic flux component is configured to generate a hysteretic current that provides a magnetic flux at an amplitude corresponding to the energy state of the tunable current element.

First claim

What is claimed is:

1. A tunable current element comprising:
a first magnetic flux component that is configured to exhibit a bias flux in response to a first control current, the bias flux decreasing relative energy barriers between discrete energy states of the tunable current element; and
a second magnetic flux component that is configured to exhibit a control flux in response to a second control current, the control flux changing a potential energy of the discrete energy states of the tunable current element to set an energy state of the tunable current element to one of the discrete energy states, such that the magnetic flux component is configured to generate a hysteretic current that provides a magnetic flux at an amplitude corresponding to the energy state of the tunable current element.

2. The element of claim 1 , wherein the first and second magnetic flux components are arranged in a series loop, the hysteretic current being generated in the series loop to provide the magnetic flux.

3. The element of claim 1 , wherein the first control current is provided via a first control line that is inductively coupled to the first magnetic flux component, such that the bias flux is induced via the first control current, wherein the second control current is provided via a second control line that is inductively coupled to the second magnetic flux component, such that the control flux is induced via the second control current.

4. The element of claim 1 , wherein the first magnetic flux component is configured as a superconducting quantum interference device (SQUID), and wherein the second magnetic flux component is configured as inductor.

5. The system of claim 4 , wherein the SQUID comprises a plurality N of Josephson junctions that are arranged in parallel with respect to each other, wherein the first control current comprises N−1 first control currents inductively coupled to a respective at least one of the N Josephson junctions.

6. A magnetic flux source system comprising the tunable current element of claim 1 , wherein the tunable current element is a first tunable current element of a plurality of tunable current elements.

7. The magnetic flux source system of claim 6 , wherein the plurality of tunable current elements are arranged in an array of rows and columns.

8. The system of claim 7 , wherein the first control current comprises a plurality of first control currents, wherein the second control current comprises a plurality of second control currents, wherein each of the plurality of first control currents are provided to one of the respective rows, and wherein each of the plurality of second control currents are provided to one of the respective columns.

9. The system of claim 7 , wherein each of the plurality of first control currents is associated with at least two of the plurality of rows or columns, wherein each of the plurality of second control currents is associated with at least two of the other of the plurality of rows or columns.

10. A circuit system comprising the magnetic flux source system of claim 6 , the circuit system further comprising at least one circuit device inductively coupled to at least one of the plurality of tunable current elements, such that the at least one of the plurality of tunable current elements is configured to inductively receive the magnetic flux from each of the at least one tunable current element.

11. A method for generating a magnetic flux via a tunable current element, the method comprising:
activating a first control current to provide the first control current to a first magnetic flux component associated with the tunable current element, such that the first control current induces a bias flux in the first magnetic flux component to decrease relative energy barriers between discrete energy states of the tunable current element;
activating a second control current to provide the second control current to a second magnetic flux component associated with the tunable current element, such that the second control current induces a control flux in the series loop to change a potential energy of the discrete energy states from a default potential energy condition of the discrete energy states of the tunable current element to set an energy state of the tunable current element to a respective one of the discrete energy states;
deactivating the first control current to increase the relative energy barriers between the discrete energy states of the tunable current element; and
deactivating the second control current to return the tunable current element to the default potential energy condition, such that the energy state of the tunable current element is maintained at the respective one of the discrete energy states based on the relative energy barriers between the discrete energy states.

12. The method of claim 11 , wherein activating the first control current comprises activating the first control current to provide the first control current on a first control line that is inductively coupled to the first magnetic flux component, wherein activating the second control current comprises activating the second control current to provide the second control current on a second control line that is inductively coupled to the second magnetic flux component.

13. The method of claim 11 , wherein activating the first control current comprises activating the first control current to provide the first control current to a superconducting quantum interference device (SQUID) associated with the tunable current element, wherein activating the second control current comprises activating the second control current to provide the second control current to an inductor associated with the tunable current element, wherein the inductor and the SQUID are arranged in a series loop.

14. The method of claim 13 , wherein the SQUID comprises a plurality of Josephson junctions that are arranged in parallel with respect to each other, the method further comprising activating at least one additional control current such that the first control current and the at least one additional control current induces the bias flux in the SQUID to decrease the relative energy barriers between the discrete energy states of the tunable current element.

15. The method of claim 11 , wherein the energy state of the tunable current element is initially set to a first energy state corresponding to a first one of the discrete energy states, the method further comprising initially activating the second control current at a first amplitude to change the potential energy of the discrete energy states to set the first energy state to a minimum energy relative to a remaining plurality of the discrete energy states before activating the first control current, wherein activating the second control current comprises changing the second control current from the first amplitude to a second amplitude to set a second energy state at the minimum energy relative to the remaining plurality of the discrete energy states before deactivating the first control current.

16. The method of claim 11 , wherein the magnetic flux is a first magnetic flux, and wherein the tunable current element is a first tunable current element of a plurality of tunable current elements arranged in an array comprising at least one row and at least one column, wherein activating the first control current comprises activating one of a plurality of first control currents that is provided on one of a plurality of first control lines corresponding to a respective first column of the array, and wherein activating the second control current comprises activating one o

Assignees

• Ferguson David George
• Novikov Sergey S
• Przybysz Anthony Joseph
• Hinkey Robert T
• Pesetski Aaron A
• Zick Kenneth M
• Northrop Grumman Systems Corp

Inventors

• Ferguson David George
• Novikov Sergey S
• Przybysz Anthony Joseph
• Hinkey Robert T
• Pesetski Aaron A
• Zick Kenneth M

Classifications

• G01R33/0358 Primary

  coupling the flux to the SQUID (gradiometer coils G01R33/022; coils with superconductive winding H01F6/06) · CPC title

• H10N69/00 Primary

  Integrated devices, or assemblies of multiple devices, comprising at least one superconducting element covered by group H10N60/00 · CPC title

• H10N60/12

  Josephson-effect devices · CPC title

• H01L39/223

  Electricity · mapped topic

• G06N10/00

  Quantum computing, i.e. information processing based on quantum-mechanical phenomena · CPC title