Patents by Inventor David George Ferguson
David George Ferguson has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11429887Abstract: One example includes a tunable current-mirror qubit. The qubit includes a plurality of flux tunable elements disposed in a circuit loop. A first portion of the flux tunable elements can be configured to receive a first input flux and a remaining portion of the flux tunable elements can be configured to receive a second input flux to control a mode of the tunable current-mirror qubit between a microwave excitation mode to facilitate excitation or quantum state manipulation of the tunable current-mirror qubit via a microwave input signal and a noise-protected mode to facilitate storage of the quantum state of the tunable current-mirror qubit. The qubit also includes at least one capacitor interconnecting nodes between respective pairs of the flux tunable elements to facilitate formation of Cooper-pair excitons in each of the microwave excitation mode and the noise-protected mode.Type: GrantFiled: March 1, 2019Date of Patent: August 30, 2022Assignees: NORTHROP GRUMMAN SYSTEMS CORPORATION, NORTHWESTERN UNIVERSITYInventors: David George Ferguson, Cheong Yiu Li, Jens Koch, Moe Shwan Khalil
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Patent number: 10989767Abstract: 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.Type: GrantFiled: October 7, 2020Date of Patent: April 27, 2021Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: David George Ferguson, Sergey S. Novikov, Anthony Joseph Przybysz, Robert T. Hinkey, Aaron A. Pesetski, Kenneth M. Zick
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Publication number: 20210033683Abstract: 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.Type: ApplicationFiled: October 7, 2020Publication date: February 4, 2021Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: DAVID GEORGE FERGUSON, SERGEY S. NOVIKOV, ANTHONY JOSEPH PRZYBYSZ, ROBERT T. HINKEY, AARON A. PESETSKI, KENNETH M. ZICK
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Patent number: 10884033Abstract: One example includes a current device readout system. The system includes a tunable resonator having a resonant frequency that is associated with a current state of a current device. The tunable resonator can be configured to receive a tone signal having a predetermined frequency from a feedline to determine the current state of the current device. The system also includes an isolation device inductively interconnecting the tunable resonator and the current device. The isolation device can be tunable to isolate the current device in a first state and to facilitate the determination of the current state of the current device in a second state.Type: GrantFiled: February 15, 2019Date of Patent: January 5, 2021Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Anthony Joseph Przybysz, David George Ferguson, Moe S. Khalil
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Patent number: 10852366Abstract: One example includes a magnetic flux source system that includes a tunable current element. The tunable current element includes a SQUID inductively coupled to a first control line that conducts a first control current that induces a bias flux in the SQUID to decrease relative energy barriers between discrete energy states of the tunable current element. The system also includes an inductor in a series loop with the SQUID and inductively coupled to a second control line that conducts a second control current that induces a control flux in the series loop to 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 to generate a current that provides a magnetic flux at an amplitude corresponding to the energy state of the at least one tunable current element.Type: GrantFiled: June 26, 2018Date of Patent: December 1, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: David George Ferguson, Sergey S. Novikov, Anthony Joseph Przybysz, Robert T. Hinkey, Aaron A. Pesetski, Kenneth M. Zick
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Publication number: 20200279186Abstract: One example includes a tunable current-mirror qubit. The qubit includes a plurality of flux tunable elements disposed in a circuit loop. A first portion of the flux tunable elements can be configured to receive a first input flux and a remaining portion of the flux tunable elements can be configured to receive a second input flux to control a mode of the tunable current-mirror qubit between a microwave excitation mode to facilitate excitation or quantum state manipulation of the tunable current-mirror qubit via a microwave input signal and a noise-protected mode to facilitate storage of the quantum state of the tunable current-mirror qubit. The qubit also includes at least one capacitor interconnecting nodes between respective pairs of the flux tunable elements to facilitate formation of Cooper-pair excitons in each of the microwave excitation mode and the noise-protected mode.Type: ApplicationFiled: March 1, 2019Publication date: September 3, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: DAVID GEORGE FERGUSON, CHEONG YIU LI, JENS KOCH, MOE SHWAN KHALIL
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Publication number: 20200264213Abstract: One example includes a current device readout system. The system includes a tunable resonator having a resonant frequency that is associated with a current state of a current device. The tunable resonator can be configured to receive a tone signal having a predetermined frequency from a feedline to determine the current state of the current device. The system also includes an isolation device inductively interconnecting the tunable resonator and the current device. The isolation device can be tunable to isolate the current device in a first state and to facilitate the determination of the current state of the current device in a second state.Type: ApplicationFiled: February 15, 2019Publication date: August 20, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Anthony Joseph Przybysz, David George Ferguson, Moe S. Khalil
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Patent number: 10749095Abstract: Systems and methods are provided for a ZZZ coupler. A first tunable coupler is coupled to the first qubit and tunable via a first control signal. A second tunable coupler is coupled to the first tunable coupler to direct a flux of the first qubit into a tuning loop of the second tunable coupler, such that when a first coupling strength associated with the first tunable coupler is non-zero, a second coupling strength, associated with the second tunable coupler, is a function of a second control signal applied to the second tunable coupler and a state of the first qubit. The second qubit and the third qubit are coupled to one another through the second tunable coupler, such that, when the second coupling strength is non-zero it is energetically favorable for the states of the first and second qubits to assume a specific relationship with respect to the Z-axis.Type: GrantFiled: November 21, 2019Date of Patent: August 18, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: David George Ferguson, Anthony Joseph Przybysz, Joel D. Strand
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Patent number: 10650323Abstract: Systems and methods are provided for coupling two flux qubits. A quantum circuit assembly includes a first flux qubit, having at least two potential energy minima, and a second flux qubit, having at least two potential energy minima. A system formed by the first and second qubits has at least four potential energy minima prior to coupling, each of the four potential energy minima containing at least one eigenstate of a system comprising the first flux qubit and the second flux qubit. A coupler creates a first tunneling path between a first potential energy minimum of the system and a second potential energy minimum of the system, and a second tunneling path between a third potential energy minimum of the system and a fourth potential energy minimum of the system. The coupler creates the first and second tunneling paths between potential energy minima representing states of equal bit parity.Type: GrantFiled: January 23, 2019Date of Patent: May 12, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Ryan J. Epstein, David George Ferguson
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Publication number: 20200091396Abstract: Systems and methods are provided for a ZZZ coupler. A first tunable coupler is coupled to the first qubit and tunable via a first control signal. A second tunable coupler is coupled to the first tunable coupler to direct a flux of the first qubit into a tuning loop of the second tunable coupler, such that when a first coupling strength associated with the first tunable coupler is non-zero, a second coupling strength, associated with the second tunable coupler, is a function of a second control signal applied to the second tunable coupler and a state of the first qubit. The second qubit and the third qubit are coupled to one another through the second tunable coupler, such that, when the second coupling strength is non-zero it is energetically favorable for the states of the first and second qubits to assume a specific relationship with respect to the Z-axis.Type: ApplicationFiled: November 21, 2019Publication date: March 19, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: DAVID GEORGE FERGUSON, ANTHONY JOSEPH PRZYBYSZ, JOEL D. STRAND
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Patent number: 10546993Abstract: Systems and methods are provided for a ZZZ coupler. A first tunable coupler is coupled to the first qubit and tunable via a first control signal. A second tunable coupler is coupled to the first tunable coupler to direct a flux of the first qubit into a tuning loop of the second tunable coupler, such that when a first coupling strength associated with the first tunable coupler is non-zero, a second coupling strength, associated with the second tunable coupler, is a function of a second control signal applied to the second tunable coupler and a state of the first qubit. The second qubit and the third qubit are coupled to one another through the second tunable coupler, such that, when the second coupling strength is non-zero it is energetically favorable for the states of the first and second qubits to assume a specific relationship with respect to the Z-axis.Type: GrantFiled: July 17, 2018Date of Patent: January 28, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: David George Ferguson, Anthony Joseph Przybysz, Joel D. Strand
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Patent number: 10540603Abstract: Real-time reconfigurability of quantum object connectivity can be provided with one or more quantum routers that can each be configured as either or both of a single-pole double-throw switch and a cross-point switch. The quantum router includes variable-inductance coupling elements in RF-SQUIDs having inductors transformer-coupled to two control flux lines, one providing a static current and the other providing a dynamic current, the direction of which can be toggled to couple or uncouple quantum objects, such as qubits, based on the dynamic current direction to provide reconfigurable quantum routing.Type: GrantFiled: June 19, 2018Date of Patent: January 21, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Ofer Naaman, Zachary Kyle Keane, Micah John Atman Stoutimore, David George Ferguson
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Publication number: 20190391214Abstract: One example includes a magnetic flux source system that includes a tunable current element. The tunable current element includes a SQUID inductively coupled to a first control line that conducts a first control current that induces a bias flux in the SQUID to decrease relative energy barriers between discrete energy states of the tunable current element. The system also includes an inductor in a series loop with the SQUID and inductively coupled to a second control line that conducts a second control current that induces a control flux in the series loop to 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 to generate a current that provides a magnetic flux at an amplitude corresponding to the energy state of the at least one tunable current element.Type: ApplicationFiled: June 26, 2018Publication date: December 26, 2019Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: DAVID GEORGE FERGUSON, SERGEY S. NOVIKOV, ANTHONY JOSEPH PRZYBYSZ, ROBERT T. HINKEY, AARON A. PESETSKI, KENNETH M. ZICK
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Publication number: 20190385088Abstract: Real-time reconfigurability of quantum object connectivity can be provided with one or more quantum routers that can each be configured as either or both of a single-pole double-throw switch and a cross-point switch. The quantum router includes variable-inductance coupling elements in RF-SQUIDs having inductors transformer-coupled to two control flux lines, one providing a static current and the other providing a dynamic current, the direction of which can be toggled to couple or uncouple quantum objects, such as qubits, based on the dynamic current direction to provide reconfigurable quantum routing.Type: ApplicationFiled: June 19, 2018Publication date: December 19, 2019Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: OFER NAAMAN, ZACHARY KYLE KEANE, MICAH JOHN ATMAN STOUTIMORE, DAVID GEORGE FERGUSON
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Patent number: 10491178Abstract: One example includes a parametric amplifier system. The system includes an input/output (I/O) transmission line to propagate a signal tone. The system also includes a non-linearity circuit comprising at least one Josephson junction to provide at least one inductive path of the signal tone in parallel with the at least one Josephson junction. The system further includes an impedance matching network coupled to the I/O transmission line to provide impedance matching of the tone signal between the I/O transmission line and the non-linearity element.Type: GrantFiled: October 31, 2017Date of Patent: November 26, 2019Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Ofer Naaman, David George Ferguson
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Patent number: 10353844Abstract: A tunable bus-mediated coupling system is provided that includes a first input port coupled to a first end of a variable inductance coupling element through a first resonator and a second input port coupled to a second end of the variable inductance coupling element through a second resonator. The first input port is configured to be coupled to a first qubit, and the second output port is configured to be coupled to a second qubit. A controller is configured to control the inductance of the variable inductance coupling element between a low inductance state to provide strong coupling between the first qubit and the second qubit and a high inductance state to provide isolation between the first qubit and the second qubit.Type: GrantFiled: July 3, 2018Date of Patent: July 16, 2019Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Ofer Naaman, Zachary Kyle Keane, Micah John Atman Stoutimore, David George Ferguson
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Publication number: 20190156237Abstract: Systems and methods are provided for coupling two flux qubits. A quantum circuit assembly includes a first flux qubit, having at least two potential energy minima, and a second flux qubit, having at least two potential energy minima. A system formed by the first and second qubits has at least four potential energy minima prior to coupling, each of the four potential energy minima containing at least one eigenstate of a system comprising the first flux qubit and the second flux qubit. A coupler creates a first tunneling path between a first potential energy minimum of the system and a second potential energy minimum of the system, and a second tunneling path between a third potential energy minimum of the system and a fourth potential energy minimum of the system. The coupler creates the first and second tunneling paths between potential energy minima representing states of equal bit parity.Type: ApplicationFiled: January 23, 2019Publication date: May 23, 2019Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: RYAN J. EPSTEIN, DAVID GEORGE FERGUSON
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Publication number: 20190131944Abstract: One example includes a parametric amplifier system. The system includes an input/output (I/O) transmission line to propagate a signal tone. The system also includes a non-linearity circuit comprising at least one Josephson junction to provide at least one inductive path of the signal tone in parallel with the at least one Josephson junction. The system further includes an impedance matching network coupled to the I/O transmission line to provide impedance matching of the tone signal between the I/O transmission line and the non-linearity element.Type: ApplicationFiled: October 31, 2017Publication date: May 2, 2019Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: OFER NAAMAN, DAVID GEORGE FERGUSON
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Patent number: 10262727Abstract: One example includes a flux qubit readout circuit. The circuit includes a gradiometric SQUID that is configured to inductively couple with a gradiometric flux qubit to modify flux associated with the gradiometric superconducting quantum interference device (SQUID) based on a flux state of the flux qubit. The circuit also includes a current source configured to provide a readout current through the gradiometric SQUID during a state readout operation to determine the flux state of the gradiometric flux qubit at a readout node.Type: GrantFiled: July 10, 2017Date of Patent: April 16, 2019Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Anthony Joseph Przybysz, David George Ferguson
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Patent number: 10255557Abstract: Systems and methods are provided for coupling two flux qubits. A quantum circuit assembly includes a first flux qubit, having at least two potential energy minima, and a second flux qubit, having at least two potential energy minima. A system formed by the first and second qubits has at least four potential energy minima prior to coupling, each of the four potential energy minima containing at least one eigenstate of a system comprising the first flux qubit and the second flux qubit. A coupler creates a first tunneling path between a first potential energy minimum of the system and a second potential energy minimum of the system, and a second tunneling path between a third potential energy minimum of the system and a fourth potential energy minimum of the system. The coupler creates the first and second tunneling paths between potential energy minima representing states of equal bit parity.Type: GrantFiled: February 15, 2017Date of Patent: April 9, 2019Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Ryan J. Epstein, David George Ferguson