Patents by Inventor Alexandre M. Zagoskin
Alexandre M. Zagoskin 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: 7015499Abstract: A solid-state quantum computing structure includes a d-wave superconductor in sets of islands that clean Josephson junctions separate from a first superconducting bank. The d-wave superconductor causes the ground state for the supercurrent at each junction to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents at the junctions create qubits for quantum computing. The quantum states can be uniformly initialized from the bank, and the crystal orientations of the islands relative to the bank influence the initial quantum state and tunneling probabilities between the ground states. A second bank, which a Josephson junction separates from the first bank, can be coupled to the islands through single electron transistors for selectably initializing one or more of the supercurrents in a different quantum state. Single electron transistors can also be used between the islands to control entanglements while the quantum states evolve.Type: GrantFiled: December 1, 1999Date of Patent: March 21, 2006Assignee: D-Wave Systems, Inc.Inventor: Alexandre M. Zagoskin
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Patent number: 7002174Abstract: A structure comprising a tank circuit inductively coupled to a flux qubit or a phase qubit. In some embodiments, a low temperature preamplifier is in electrical communication with the tank circuit. The tank circuit comprises an effective capacitance and an effective inductance that are in parallel or in series. In some embodiments, the effective inductance comprises a multiple winding coil of wire. A method that includes the steps of (i) providing a tank circuit and a phase qubit that are inductively coupled, (ii) reading out a state of the phase qubit, (iii) applying a flux to the phase qubit that approaches a net zero flux, (iv) increasing a level of flux applied to the phase qubit, and (v) observing a response of the tank circuit in a readout device.Type: GrantFiled: December 16, 2002Date of Patent: February 21, 2006Assignee: D-Wave Systems, Inc.Inventors: Evgeni Il'ichev, Miroslav Grajcar, Alexandre M. Zagoskin, Miles F. H. Steininger
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Patent number: 6979836Abstract: A superconducting structure that can operate, for example, as a qubit or a superconducting switch is presented. The structure includes a loop formed from two parts. A first part includes two superconducting materials separated by a junction. The junction can, for example, be a 45° grain boundary junction. The second part can couple the two superconducting materials across the junction. The second part includes a superconducting material coupled to each of the two superconducting materials of the first part through c-axis junctions. Further embodiments of the invention can be as a coherent unconventional superconducting switch, or a variable phase shift unconventional superconductor junction device.Type: GrantFiled: August 29, 2002Date of Patent: December 27, 2005Assignee: D-Wave Systems, Inc.Inventors: Alexandre M. Zagoskin, Alexander Ya. Tzalenchuk, Jeremy P. Hilton
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Patent number: 6960780Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: GrantFiled: March 15, 2004Date of Patent: November 1, 2005Assignee: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Patent number: 6930320Abstract: A method is provided for entangling a quantum state of a qubit with a quantum state of a resonant control system. The method comprises tuning the resonant control system, which is capacitively or inductively coupled to the qubit, to a resonant frequency for a period of time. The resonant frequency corresponds to an energy difference between a first energy level of the qubit and a second energy level of the qubit. The act of tuning entangles the quantum state of the qubit with the quantum state of the resonant control system. A representative resonant control system includes a Josephson junction. A method is also provided for entangling a quantum state of a qubit, within a plurality of qubits, with a quantum state of a resonant control system.Type: GrantFiled: March 10, 2004Date of Patent: August 16, 2005Assignee: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Patent number: 6900454Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: GrantFiled: April 17, 2003Date of Patent: May 31, 2005Assignee: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Patent number: 6900456Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: GrantFiled: March 15, 2004Date of Patent: May 31, 2005Assignee: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Patent number: 6897468Abstract: Methods for coupling a superconducting qubit to a resonant control circuit. An interaction term between the qubit and the circuit initially has a diagonal component. A recoupling operation is applied to the qubit. The circuit is tuned so that a frequency of the qubit and circuit match. A second recoupling operation transforms the term to have only off-diagonal components. A method for entangling a state of two qubits coupled to a bus with a control circuit. An interaction term between at least one of the qubits and the circuit has a diagonal component. A recoupling operation is applied to at least one of the qubits such that the term has only off-diagonal components. The frequency of the circuit is tuned to the frequency of the first qubit, and then tuned to the frequency of the second qubit. The recoupling operation is reapplied to at least one of the qubits.Type: GrantFiled: March 15, 2004Date of Patent: May 24, 2005Assignee: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Publication number: 20040173792Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: ApplicationFiled: March 15, 2004Publication date: September 9, 2004Applicant: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jermey P. Hilton, Alexandre M. Zagoskin
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Publication number: 20040173787Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: ApplicationFiled: March 15, 2004Publication date: September 9, 2004Applicant: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Publication number: 20040173793Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: ApplicationFiled: March 15, 2004Publication date: September 9, 2004Applicant: D-Wave Systems, Inc.Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Publication number: 20040077503Abstract: A circuit comprising a superconducting qubit and a resonant control system that is characterized by a resonant frequency. The resonant frequency of the control system is a function of a bias current. The circuit further includes a superconducting mechanism having a capacitance or inductance. The superconducting mechanism coherently couples the superconducting qubit to the resonant control system. A method for entangling a quantum state of a first qubit with the quantum state of a second qubit. In the method, a resonant control system, which is capacitively coupled to the first and second qubit, is tuned to a first frequency that corresponds to the energy differential between the lowest two potential energy levels of the first qubit. The resonant control system is then adjusted to a second frequency corresponding to energy differential between the lowest two potential energy levels of the second qubit.Type: ApplicationFiled: April 17, 2003Publication date: April 22, 2004Inventors: Alexandre Blais, Jeremy P. Hilton, Alexandre M. Zagoskin
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Publication number: 20030224944Abstract: A structure comprising a tank circuit inductively coupled to a flux qubit or a phase qubit. In some embodiments, a low temperature preamplifier is in electrical communication with the tank circuit. The tank circuit comprises an effective capacitance and an effective inductance that are in parallel or in series. In some embodiments, the effective inductance comprises a multiple winding coil of wire. A method that includes the steps of (i) providing a tank circuit and a phase qubit that are inductively coupled, (ii) reading out a state of the phase qubit, (iii) applying a flux to the phase qubit that approaches a net zero flux, (iv) increasing a level of flux applied to the phase qubit, and (v) observing a response of the tank circuit in a readout device.Type: ApplicationFiled: December 16, 2002Publication date: December 4, 2003Inventors: Evgeni Il'ichev, Miroslav Grajcar, Alexandre M. Zagoskin, Miles F. H. Steininger
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Patent number: 6563311Abstract: A solid-state quantum computing structure includes a d-wave superconductor in sets of islands that clean Josephson junctions separate from a first superconducting bank. The d-wave superconductor causes the ground state for the supercurrent at each junction to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents at the junctions create qubits for quantum computing. The quantum states can be uniformly initialized from the bank, and the crystal orientations of the islands relative to the bank influence the initial quantum state and tunneling probabilities between the ground states. A second bank, which a Josephson junction separates from the first bank, can be coupled to the islands through single electron transistors for selectably initializing one or more of the supercurrents in a different quantum state. Single electron transistors can also be used between the islands to control entanglements while the quantum states evolve.Type: GrantFiled: May 14, 2001Date of Patent: May 13, 2003Assignee: D-Wave Systems, Inc.Inventor: Alexandre M. Zagoskin
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Patent number: 6563310Abstract: A solid-state quantum computing structure includes a set of islands that Josephson junctions separate from a first superconducting bank. A d-wave superconductor is on one side of the Josephson junctions (either the islands' side or the bank's side), and an s-wave superconductor forms the other side of the Josephson junctions. The d-wave superconductor causes the ground state for the supercurrent at each junction to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents at the junctions create qubits for quantum computing. The quantum states can be uniformly initialized from the bank, and the crystal orientations of the islands relative to the bank influence the initial quantum state and tunneling probabilities between the ground states.Type: GrantFiled: May 14, 2001Date of Patent: May 13, 2003Assignee: D-Wave Systems, Inc.Inventor: Alexandre M. Zagoskin
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Publication number: 20030071258Abstract: A superconducting structure that can operate, for example, as a qubit or a superconducting switch is presented. The structure includes a loop formed from two parts. A first part includes two superconducting materials separated by a junction. The junction can, for example, be a 45° grain boundary junction. The second part can couple the two superconducting materials across the junction. The second part includes a superconducting material coupled to each of the two superconducting materials of the first part through c-axis junctions. Further embodiments of the invention can be as a coherent unconventional superconducting switch, or a variable phase shift unconventional superconductor junction device.Type: ApplicationFiled: August 29, 2002Publication date: April 17, 2003Inventors: Alexandre M. Zagoskin, Alexander Ya Tzalenchuk, Jeremy P. Hilton
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Publication number: 20030063426Abstract: An optical device having an optical microsphere. Resonant electromagnetic radiation is trapped in the microsphere and manipulated with externally applied electric and magnetic fields to control polarization components of the excited energy within the microsphere. The optical microsphere can be used as a signal inverter. In the single photon regime, the optical microsphere can be used as a mechanism for entangling qubit states coded by the polarization states of whispering gallery modes excited in the microsphere. Furthermore, the device can be used as a switch for the absorption or reflection of photons in response to control photons.Type: ApplicationFiled: August 29, 2002Publication date: April 3, 2003Applicant: D-Wave Systems, Inc.Inventors: Anatoly Yu Smirnov, Sergey Rashkeev, Alexandre M. Zagoskin, Jeremy P. Hilton
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Patent number: 6537847Abstract: A method is described for forming a solid state qubit. The method includes forming a dot or an anti-dot. The dot or anti-dot can be formed on a substrate and is delimited by an interface that defines a closed area. The dot or anti-dot includes a superconductive material with Cooper pairs that are in a state of non-zero orbital angular momentum on at least one side of the interface. The method includes removing superconducting material on the inner side of the interface or removing the outer side of the interface by etching. The method can further include forming a dot or an anti-dot by damaging the superconducting material such that the superconductive material becomes non-superconductive in predefined areas. The damaging of superconducting material can be performed by irradiation with particles, such as alpha particles or neutrons. The superconductive material can also be formed by doping a non-superconductive material.Type: GrantFiled: January 25, 2002Date of Patent: March 25, 2003Assignee: D-Wave Systems, Inc.Inventors: Alexandre M. Zagoskin, Geordie Rose, Mohammad H. S. Amin, Marcel Franz, Jeremy P. Hilton
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Patent number: 6504172Abstract: A solid-state quantum computing structure includes a dot of superconductive material, where the superconductor possesses a dominant order parameter with a non-zero angular momentum and a sub-dominant order parameter that can have any pairing symmetry. Alternately a solid-state quantum computing structure includes an anti-dot, which is a region in a superconductor where the order parameter is suppressed. In either embodiment of the invention, circulating persistent currents are generated via time-reversal symmetry breaking effects in the boundaries between superconducting and insulating materials. These effects cause the ground state for the supercurrent circulating near the qubit to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents store quantum information, which creates the basis of qubits for quantum computing.Type: GrantFiled: March 16, 2001Date of Patent: January 7, 2003Assignee: D-Wave Systems, Inc.Inventors: Alexandre M. Zagoskin, Geordie Rose, Mohammad H. S. Amin, Marcel Franz, Jeremy P. Hilton
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Patent number: 6459097Abstract: A solid-state quantum computing structure includes a set of islands that Josephson junctions separate from a first superconducting bank. A d-wave superconductor is on one side of the Josephson junctions (either the islands' side or the bank's side), and an s-wave superconductor forms the other side of the Josephson junctions. The d-wave superconductor causes the ground state for the supercurrent at each junction to be doubly degenerate, with two supercurrent ground states having distinct magnetic moments. These quantum states of the supercurrents at the junctions create qubits for quantum computing. The quantum states can be uniformly initialized from the bank, and the crystal orientations of the islands relative to the bank influence the initial quantum state and tunneling probabilities between the ground states.Type: GrantFiled: January 7, 2000Date of Patent: October 1, 2002Assignee: D-Wave Systems Inc.Inventor: Alexandre M. Zagoskin