Patents by Inventor Thomas F. Ambrose
Thomas F. Ambrose 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).
-
Patent number: 11631797Abstract: A buffer layer can be used to smooth the surface roughness of a galvanic contact layer (e.g., of niobium) in an electronic device, the buffer layer being made of a stack of at least four (e.g., six) layers of a face-centered cubic (FCC) crystal structure material, such as copper, the at least four FCC material layers alternating with at least three layers of a body-centered cubic (BCC) crystal structure material, such as niobium, wherein each of the FCC material layers and BCC material layers is between about five and about ten angstroms thick. The buffer layer can provide the smoothing while still maintaining desirable transport properties of a device in which the buffer layer is used, such as a magnetic Josephson junction, and magnetics of an overlying magnetic layer in the device, thereby permitting for improved magnetic Josephson junctions (MJJs) and thus improved superconducting memory arrays and other devices.Type: GrantFiled: November 11, 2020Date of Patent: April 18, 2023Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Thomas F. Ambrose, Melissa G. Loving
-
Patent number: 11342491Abstract: One example includes a magnetic Josephson junction (MJJ) system. The system includes a first superconducting material layer and a second superconducting material layer each configured respectively as a galvanic contacts. The system also includes a ferrimagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a fixed net magnetic moment at a predetermined operating temperature of the MJJ system. The system also includes a ferromagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a variable magnetic orientation in response to an applied magnetic field. The MJJ system can be configured to store a binary logical value based on a direction of the variable magnetic orientation of the ferromagnetic material layer. The system further includes a spacer layer arranged between the ferromagnetic and the ferrimagnetic material layers.Type: GrantFiled: September 28, 2020Date of Patent: May 24, 2022Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Thomas F. Ambrose, Melissa G. Loving, Alastair Charlie Fisher
-
Patent number: 11316099Abstract: A memory device includes a memory stack formed on a substrate to program skyrmions within at least one layer of the stack. The skyrmions represent logic states of the memory device. The memory stack further includes a top and bottom electrode to receive electrical current from an external source and to provide the electrical current to the memory stack. A free layer stores a logic state of the skyrmions in response to the electrical current. A Dzyaloshinskii-Moriya (DM) Interaction (DMI) layer in contact with the free layer induces skyrmions in the free layer. A tunnel barrier is interactive with the DMI layer to facilitate detection of the logic state of the skyrmions in response to a read current. At least one fixed magnetic (FM) layer is positioned within the memory stack to facilitate programming of the skyrmions within the free layer in response to the electrical current.Type: GrantFiled: June 5, 2020Date of Patent: April 26, 2022Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Michael M. Fitelson, Thomas F. Ambrose, Nicholas D. Rizzo
-
Publication number: 20220102611Abstract: One example includes a magnetic Josephson junction (MJJ) system. The system includes a first superconducting material layer and a second superconducting material layer each configured respectively as a galvanic contacts. The system also includes a ferrimagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a fixed net magnetic moment at a predetermined operating temperature of the MJJ system. The system also includes a ferromagnetic material layer arranged between the first and second superconducting material layers and that is configured to exhibit a variable magnetic orientation in response to an applied magnetic field. The MJJ system can be configured to store a binary logical value based on a direction of the variable magnetic orientation of the ferromagnetic material layer. The system further includes a spacer layer arranged between the ferromagnetic and the ferrimagnetic material layers.Type: ApplicationFiled: September 28, 2020Publication date: March 31, 2022Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: THOMAS F. AMBROSE, MELISSA G. LOVING, ALASTAIR CHARLIE FISHER
-
Patent number: 11211117Abstract: A magnetic Josephson junction (MJJ) device having a ferrimagnetic/ferromagnetic (FIM/FM) exchange-biased bilayer used as the magnetic hard layer improves switching performance by effectively sharpening the hysteresis curve of the device, thereby reducing error rate when the device is used in a Josephson magnetic random access memory (JMRAM) memory cell. Thus, the materials and devices described herein can be used to build a new type of MJJ, termed a ferrimagnetic Josephson junction (FIMJJ), for use in JMRAM, to construct a robust and reliable cryogenic computer memory that can be used for high-speed superconducting computing, e.g., with clock speeds in the microwave frequency range.Type: GrantFiled: January 24, 2019Date of Patent: December 28, 2021Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Melissa G. Loving, Thomas F. Ambrose
-
Patent number: 11047817Abstract: A sealed container having gloves attached thereto is provided as part of a physical properties measuring system (PPMS). The PPMS includes a sealed pressurized portion that is pressurized with a gas to purge out air from inside the sealed pressurized portion to reduce water vapor inside the sealed pressurized portion below a water vapor threshold. The system further includes a cryogenic tank having a cryostat disposed therein. The cryogenic tank contains a cryogenic liquid cooled to a cryogenic temperature. Test samples are placed inside the sealed pressurized portion in preparation of measuring physical properties of the test samples. One of the test samples is immersed in the cryogenic liquid to measure the physical properties. The test sample is removed from the cryogenic liquid and is exchanged for another test sample inside the sealed pressurized portion to prevent ice formation inside the cryostat.Type: GrantFiled: April 17, 2019Date of Patent: June 29, 2021Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Kurt Edward Dietrich, Thomas F. Ambrose, Eric C. Gingrich, Timothy Richard Barbour
-
Patent number: 11024791Abstract: A memory cell is provided that comprises a first superconductor electrode, a second superconductor electrode, and a magnetic Josephson junction (MJJ) stack disposed between the first superconductor electrode and the second superconductor electrode. The MJJ stack includes a magnetic reference layer and a magnetic storage layer. The memory cell further comprises a magnetically stabilizing structure disposed between the MJJ stack and the second superconductor electrode, wherein the magnetic stabilizing structure magnetically couples with the magnetic reference layer to strengthen the fixed state of the magnetic reference layer.Type: GrantFiled: January 27, 2020Date of Patent: June 1, 2021Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: James Matthew Murduck, Melissa G. Loving, Thomas F. Ambrose
-
Publication number: 20210066572Abstract: A buffer layer can be used to smooth the surface roughness of a galvanic contact layer (e.g., of niobium) in an electronic device, the buffer layer being made of a stack of at least four (e.g., six) layers of a face-centered cubic (FCC) crystal structure material, such as copper, the at least four FCC material layers alternating with at least three layers of a body-centered cubic (BCC) crystal structure material, such as niobium, wherein each of the FCC material layers and BCC material layers is between about five and about ten angstroms thick. The buffer layer can provide the smoothing while still maintaining desirable transport properties of a device in which the buffer layer is used, such as a magnetic Josephson junction, and magnetics of an overlying magnetic layer in the device, thereby permitting for improved magnetic Josephson junctions (MJJs) and thus improved superconducting memory arrays and other devices.Type: ApplicationFiled: November 11, 2020Publication date: March 4, 2021Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: THOMAS F. AMBROSE, MELISSA G. LOVING
-
Patent number: 10910544Abstract: Superconducting circuits and memories that use a magnetic Josephson junction (MJJ) device as a pi inverter are disclosed. The MJJ device includes superconducting layers configured to allow a flow of a supercurrent through the MJJ device. The MJJ device further includes a magnetic layer arranged between the superconducting layers, where the magnetic layer has an associated magnetization direction, and where the first state of the MJJ device corresponds to a zero-phase of a supercurrent flowing through the MJJ device and the second state of the MJJ device corresponds to a ?-phase of the supercurrent flowing through the MJJ device. In response to an application of a magnetic field, without any change in the magnetization direction of the magnetic layer, the MJJ device is configured to switch from the first state to the second state responsive to a change in a phase of the supercurrent.Type: GrantFiled: February 26, 2019Date of Patent: February 2, 2021Assignee: Microsoft Technology Licensing, LLCInventors: Thomas F. Ambrose, James M. Murduck
-
Patent number: 10879447Abstract: A buffer layer can be used to smooth the surface roughness of a galvanic contact layer (e.g., of niobium) in an electronic device, the buffer layer being made of a stack of at least four (e.g., six) layers of a face-centered cubic (FCC) crystal structure material, such as copper, the at least four FCC material layers alternating with at least three layers of a body-centered cubic (BCC) crystal structure material, such as niobium, wherein each of the FCC material layers and BCC material layers is between about five and about ten angstroms thick. The buffer layer can provide the smoothing while still maintaining desirable transport properties of a device in which the buffer layer is used, such as a magnetic Josephson junction, and magnetics of an overlying magnetic layer in the device, thereby permitting for improved magnetic Josephson junctions (MJJs) and thus improved superconducting memory arrays and other devices.Type: GrantFiled: March 13, 2019Date of Patent: December 29, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Thomas F. Ambrose, Melissa G. Loving
-
Publication number: 20200332958Abstract: A sealed container having gloves attached thereto is provided as part of a physical properties measuring system (PPMS). The PPMS includes a sealed pressurized portion that is pressurized with a gas to purge out air from inside the sealed pressurized portion to reduce water vapor inside the sealed pressurized portion below a water vapor threshold. The system further includes a cryogenic tank having a cryostat disposed therein. The cryogenic tank contains a cryogenic liquid cooled to a cryogenic temperature. Test samples are placed inside the sealed pressurized portion in preparation of measuring physical properties of the test samples. One of the test samples is immersed in the cryogenic liquid to measure the physical properties. The test sample is removed from the cryogenic liquid and is exchanged for another test sample inside the sealed pressurized portion to prevent ice formation inside the cryostat.Type: ApplicationFiled: April 17, 2019Publication date: October 22, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: KURT EDWARD DIETRICH, THOMAS F. AMBROSE, ERIC C. GINGRICH, TIMOTHY RICHARD BARBOUR
-
Publication number: 20200303633Abstract: A memory device includes a memory stack formed on a substrate to program skyrmions within at least one layer of the stack. The skyrmions represent logic states of the memory device. The memory stack further includes a top and bottom electrode to receive electrical current from an external source and to provide the electrical current to the memory stack. A free layer stores a logic state of the skyrmions in response to the electrical current. A Dzyaloshinskii-Moriya (DM) Interaction (DMI) layer in contact with the free layer induces skyrmions in the free layer. A tunnel barrier is interactive with the DMI layer to facilitate detection of the logic state of the skyrmions in response to a read current. At least one fixed magnetic (FM) layer is positioned within the memory stack to facilitate programming of the skyrmions within the free layer in response to the electrical current.Type: ApplicationFiled: June 5, 2020Publication date: September 24, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: MICHAEL M. FITELSON, THOMAS F. AMBROSE, NICHOLAS D. RIZZO
-
Publication number: 20200295249Abstract: A buffer layer can be used to smooth the surface roughness of a galvanic contact layer (e.g., of niobium) in an electronic device, the buffer layer being made of a stack of at least four (e.g., six) layers of a face-centered cubic (FCC) crystal structure material, such as copper, the at least four FCC material layers alternating with at least three layers of a body-centered cubic (BCC) crystal structure material, such as niobium, wherein each of the FCC material layers and BCC material layers is between about five and about ten angstroms thick. The buffer layer can provide the smoothing while still maintaining desirable transport properties of a device in which the buffer layer is used, such as a magnetic Josephson junction, and magnetics of an overlying magnetic layer in the device, thereby permitting for improved magnetic Josephson junctions (MJJs) and thus improved superconducting memory arrays and other devices.Type: ApplicationFiled: March 13, 2019Publication date: September 17, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: THOMAS F. AMBROSE, MELISSA G. LOVING
-
Publication number: 20200274049Abstract: Superconducting circuits and memories that use a magnetic Josephson junction (MJJ) device as a pi inverter are disclosed. The MJJ device includes superconducting layers configured to allow a flow of a supercurrent through the MJJ device. The MJJ device further includes a magnetic layer arranged between the superconducting layers, where the magnetic layer has an associated magnetization direction, and where the first state of the MJJ device corresponds to a zero-phase of a supercurrent flowing through the MJJ device and the second state of the MJJ device corresponds to a ?-phase of the supercurrent flowing through the MJJ device. In response to an application of a magnetic field, without any change in the magnetization direction of the magnetic layer, the MJJ device is configured to switch from the first state to the second state responsive to a change in a phase of the supercurrent.Type: ApplicationFiled: February 26, 2019Publication date: August 27, 2020Inventors: Thomas F. Ambrose, James M. Murduck
-
Publication number: 20200259074Abstract: A memory device includes a memory stack formed on a substrate to program skyrmions within at least one layer of the stack. The skyrmions represent logic states of the memory device. The memory stack further includes a top and bottom electrode to receive electrical current from an external source and to provide the electrical current to the memory stack. A free layer stores a logic state of the skyrmions in response to the electrical current. A Dzyaloshinskii-Moriya (DM) Interaction (DMI) layer in contact with the free layer induces skyrmions in the free layer. A tunnel barrier is interactive with the DMI layer to facilitate detection of the logic state of the skyrmions in response to a read current. At least one fixed magnetic (FM) layer is positioned within the memory stack to facilitate programming of the skyrmions within the free layer in response to the electrical current.Type: ApplicationFiled: February 12, 2019Publication date: August 13, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: MICHAEL M. FITELSON, THOMAS F. AMBROSE, NICHOLAS D. RIZZO
-
Publication number: 20200243132Abstract: A magnetic Josephson junction (MJJ) device having a ferrimagnetic/ferromagnetic (FIM/FM) exchange-biased bilayer used as the magnetic hard layer improves switching performance by effectively sharpening the hysteresis curve of the device, thereby reducing error rate when the device is used in a Josephson magnetic random access memory (JMRAM) memory cell. Thus, the materials and devices described herein can be used to build a new type of MJJ, termed a ferrimagnetic Josephson junction (FIMJJ), for use in JMRAM, to construct a robust and reliable cryogenic computer memory that can be used for high-speed superconducting computing, e.g., with clock speeds in the microwave frequency range.Type: ApplicationFiled: January 24, 2019Publication date: July 30, 2020Applicant: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: MELISSA G. LOVING, THOMAS F. AMBROSE
-
Patent number: 10720572Abstract: A memory device includes a memory stack formed on a substrate to program skyrmions within at least one layer of the stack. The skyrmions represent logic states of the memory device. The memory stack further includes a top and bottom electrode to receive electrical current from an external source and to provide the electrical current to the memory stack. A free layer stores a logic state of the skyrmions in response to the electrical current. A Dzyaloshinskii-Moriya (DM) Interaction (DMI) layer in contact with the free layer induces skyrmions in the free layer. A tunnel barrier is interactive with the DMI layer to facilitate detection of the logic state of the skyrmions in response to a read current. At least one fixed magnetic (FM) layer is positioned within the memory stack to facilitate programming of the skyrmions within the free layer in response to the electrical current.Type: GrantFiled: February 12, 2019Date of Patent: July 21, 2020Assignee: NORTHROP GRUMMAN SYSTEMS CORPORATIONInventors: Michael M. Fitelson, Thomas F. Ambrose, Nicholas D. Rizzo
-
Patent number: 10546621Abstract: Magnetic Josephson junction driven flux-biased superconductor memory cell and methods are provided. A memory cell may include a magnetic Josephson junction (MJJ) superconducting quantum interference device (SQUID) comprising a first MJJ device and a second MJJ device, arranged in parallel to each other, where the MJJ SQUID is configured to generate a first flux-bias or a second flux-bias, where the first flux-bias corresponds to a first direction of current flow in the MJJ SQUID and the second flux-bias corresponds to a second direction of current flow in the MJJ SQUID. The memory cell may further include a superconducting metal-based superconducting quantum interference device (SQUID) including a first Josephson junction (JJ) and a second JJ, arranged in parallel to each other, where each of the first JJ and the second JJ has a critical current responsive to any flux-bias generated by the MJJ SQUID.Type: GrantFiled: June 20, 2018Date of Patent: January 28, 2020Assignee: Microsoft Technology Licensing, LLCInventors: James M. Murduck, Thomas F. Ambrose
-
Publication number: 20190392878Abstract: Magnetic Josephson junction driven flux-biased superconductor memory cell and methods are provided. A memory cell may include a magnetic Josephson junction (MJJ) superconducting quantum interference device (SQUID) comprising a first MJJ device and a second MJJ device, arranged in parallel to each other, where the MJJ SQUID is configured to generate a first flux-bias or a second flux-bias, where the first flux-bias corresponds to a first direction of current flow in the MJJ SQUID and the second flux-bias corresponds to a second direction of current flow in the MJJ SQUID. The memory cell may further include a superconducting metal-based superconducting quantum interference device (SQUID) including a first Josephson junction (JJ) and a second JJ, arranged in parallel to each other, where each of the first JJ and the second JJ has a critical current responsive to any flux-bias generated by the MJJ SQUID.Type: ApplicationFiled: June 20, 2018Publication date: December 26, 2019Inventors: James M. Murduck, Thomas F. Ambrose
-
Patent number: 10242725Abstract: Apparatus and method contemplating a magnetoresistive memory apparatus having a read element having a high resistance material selected to optimize read sensitivity and a write element having a material selected for a lower critical current response than the read element critical current response to optimize switching efficiency, wherein the read element resistance is higher than the write element resistance, and a shared storage space for both elements.Type: GrantFiled: September 1, 2017Date of Patent: March 26, 2019Assignee: Seagate Technology, LLCInventors: Oleg N. Mryasov, Thomas F. Ambrose, Werner Scholz