Patents by Inventor Kae Nemoto
Kae Nemoto 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: 9111229Abstract: A method is provided of creating an end-to-end entanglement (87) between qubits in first and second end nodes (81, 82) of a chain of optically-coupled nodes whose intermediate nodes (80) are quantum repeaters. Local entanglements (85) are created on an on-going basis between qubits in neighboring pairs in the chain through interaction of the qubits with light fields transmitted between the nodes. The quantum repeaters (80) are cyclically operated with their top-level operating cycles being synchronized. Once every top-level operating cycle, each repeater (80) initiates a merging of two entanglements involving respective repeater qubits that are at least expected to be entangled with qubits in nodes disposed in opposite directions along the chain from the repeater. A quantum repeater (80) adapted for implementing this method is also provided.Type: GrantFiled: October 26, 2009Date of Patent: August 18, 2015Assignees: Hewlett-Packard Development Company, L.P., Inter-University Research Institute Corporation Research Organization of Information and SystemsInventors: Keith Harrison, William Munro, Kae Nemoto
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Patent number: 8781334Abstract: An iterative method is provided for progressively building an end-to-end entanglement between qubits in first and second end nodes (91, 92) of a chain of nodes whose intermediate nodes (90) are quantum repeaters. At each iteration, a current operative repeater (90) of the chain merges an entanglement existing between qubits in the first end node (91) and the operative repeater, with a local entanglement formed between qubits in the operative repeater and its neighbor node towards the second end node (92). For the first iteration, the operative repeater is the neighbor of the first end node (91); thereafter, for each new iteration the operative repeater shifts one node further along the chain toward the second end node (92). A quantum repeater adapted for implementing this method is also provided.Type: GrantFiled: October 26, 2009Date of Patent: July 15, 2014Inventors: William Munro, Keith Harrison, Timothy Spiller, Kae Nemoto
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Publication number: 20120148237Abstract: A method is provided of creating an end-to-end entanglement (87) between qubits in first and second end nodes (81, 82) of a chain of optically-coupled nodes whose intermediate nodes (80) are quantum repeaters. Local entanglements (85) are created on an on-going basis between qubits in neighbouring pairs in the chain through interaction of the qubits with light fields transmitted between the nodes. The quantum repeaters (80) are cyclically operated with their top-level operating cycles being synchronized. Once every top-level operating cycle, each repeater (80) initiates a merging of two entanglements involving respective repeater qubits that are at least expected to be entangled with qubits in nodes disposed in opposite directions along the chain from the repeater. A quantum repeater (80) adapted for implementing this method is also provided.Type: ApplicationFiled: October 26, 2009Publication date: June 14, 2012Inventors: Keith Harrison, William Munro, Kae Nemoto
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Publication number: 20120134675Abstract: An iterative method is provided for progressively building an end-to-end entanglement between qubits in first and second end nodes (91, 92) of a chain of nodes whose intermediate nodes (90) are quantum repeaters. At each iteration, a current operative repeater (90) of the chain merges an entanglement existing between qubits in the first end node (91) and the operative repeater, with a local entanglement formed between qubits in the operative repeater and its neighbour node towards the second end node (92). For the first iteration, the operative repeater is the neighbour of the first end node (91); thereafter, for each new iteration the operative repeater shifts one node further along the chain toward the second end node (92). A quantum repeater adapted for implementing this method is also provided.Type: ApplicationFiled: October 26, 2009Publication date: May 31, 2012Inventors: William Munro, Keith Harrison, Timothy Spiller, Kae Nemoto
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Publication number: 20120093521Abstract: A method is provided of creating an end-to-end entanglement (89) between qubits in first and second end nodes (81L, 81R) of a chain of optically-coupled nodes whose intermediate nodes (80) are quantum repeaters. Local entanglements (85) are created between qubits in neighbouring pairs in the chain through interaction of the qubits with light fields transmitted between the nodes. A trigger (82) propagated along the chain from one end node (81L), sequentially enables each quantum repeater (100; 210) to effect a top-level cycle of operation. In each such cycle, a repeater (80) initiates a merging of two entanglements involving respective repeater qubits that are at least expected to be entangled with qubits in nodes disposed in opposite directions along the chain from the repeater. A quantum repeater (80) adapted for implementing this method is also provided.Type: ApplicationFiled: October 26, 2009Publication date: April 19, 2012Inventors: Keith Harrison, William Munro, Kae Nemoto
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Patent number: 8135276Abstract: A quantum repeater includes a transmitter portion including a source, a set of matter systems, and an optical system. The source produces a probe pulse in a probe state having components with different photon numbers, and each matter system has at least one state that interacts with photons in the probe pulse to introduce a change in a phase space location of the probe state. The optical system can direct the probe pulse for interaction with one of the matter systems and direct light from the matter system for transmission on a first channel.Type: GrantFiled: August 11, 2006Date of Patent: March 13, 2012Assignee: Hewlett-Packard Development Company, L.P.Inventors: William J. Munro, Kae Nemoto, Peter Van Loock, Yoshihisa Yamamoto
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Publication number: 20120050834Abstract: A method and apparatus (70) are provided for creating an entanglement between two qubits situated in spaced nodes (71, 72) and coupled by an optical channel (75). One node (71) supports a plurality of qubits (73) and is arranged to pass a respective light field through each qubit and on into the optical channel (75), so as to produce a train (78) of closely-spaced light fields on the optical channel (75). The other node (72) supports a target qubit (74) and is arranged to receive the light-field train (78), to allow each successive light field to pass through, and potentially interact with, the target qubit (74) while the latter remains un-entangled, and to thereafter measure each light field to determine whether the latter has been successfully entangled. Upon the second node (72) determining that the target qubit (74) has become entangled, it inhibits the interaction of further light fields with the target qubit.Type: ApplicationFiled: October 26, 2009Publication date: March 1, 2012Inventors: Keith Harrison, William Munro, Kae Nemoto
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Patent number: 8023828Abstract: Structures and methods allow: transfer of quantum information represented using the states of light to a representation using the states of matter systems; transfer of quantum information represented by the states of matter systems to a representation using the states of light; and error resistant encoding of quantum information using entangled states of matter and light to minimize errors.Type: GrantFiled: October 17, 2005Date of Patent: September 20, 2011Assignee: Hewlett-Packard Development Company, L.P.Inventors: Raymond G. Beausoleil, William J. Munro, Timothy P. Spiller, Kae Nemoto
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Patent number: 7836007Abstract: Various embodiments of the present invention are directed to methods for generating an entangled state of qubits. In one embodiment of the present invention, a method for preparing an entangled state of qubits comprises providing a probe and N non-interacting qubits, each qubit comprises a linear superposition of two basis states. The probe is transmitted into an interaction region that separately couples the probe to each of the qubits and produces a number of different probes. A linear superposition of states is output from the interaction region, each state in the linear superposition of states comprises a tensor product of entangled basis states and one of the different probes. The linear superposition of states is projected into one of the entangled states by measuring the state of the probe.Type: GrantFiled: January 30, 2006Date of Patent: November 16, 2010Assignee: Hewlett-Packard Development Company, L.P.Inventors: Raymond G. Beausoleil, William J. Munro, Timothy P. Spillar, Pieter Kok, Sean D. Barrett, Kae Nemoto
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Patent number: 7791780Abstract: Nonlinear elements can efficiently implement quantum information processing systems such as controlled phase shifters, non-absorbing detectors including parity detectors, quantum subspace projections, non-absorbing Bell state analyzers, non-absorbing encoders/entanglers, and fundamental quantum gates such as CNOT gates. The non-absorbing detectors permit improvements in the efficiency of a probabilistic quantum gate by permitting reuse of the same photonic resources during multiple passes through the probabilistic gate.Type: GrantFiled: June 28, 2005Date of Patent: September 7, 2010Assignee: Hewlett-Packard Development Company, L.P.Inventors: William J. Munro, Timothy P. Spiller, Kae Nemoto
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Publication number: 20090097862Abstract: A quantum repeater includes a transmitter portion including a source, a set of matter systems, and an optical system. The source produces a probe pulse in a probe state having components with different photon numbers, and each matter system has at least one state that interacts with photons in the probe pulse to introduce a change in a phase space location of the probe state. The optical system can direct the probe pulse for interaction with one of the matter systems and direct light from the matter system for transmission on a first channel.Type: ApplicationFiled: August 11, 2006Publication date: April 16, 2009Inventors: William J. Munro, kae Nemoto, Peter Van Loock, Yoshihisa Yamamoto
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Publication number: 20080310000Abstract: Nonlinear elements can efficiently implement quantum information processing systems such as controlled phase shifters, non-absorbing detectors including parity detectors, quantum subspace projections, non-absorbing Bell state analyzers, non-absorbing encoders/entanglers, and fundamental quantum gates such as CNOT gates. The non-absorbing detectors permit improvements in the efficiency of a probabilistic quantum gate by permitting reuse of the same photonic resources during multiple passes through the probabilistic gate.Type: ApplicationFiled: June 28, 2005Publication date: December 18, 2008Inventors: Raymond G. Beausoleil, JR., William J. Munro, Timothy P. Spiller, Sean D. Barrett, Pieter Kok, Kae Nemoto
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Patent number: 7449672Abstract: Systems and methods convert or transfer quantum information from one photonic representation or state to another. This permits conversion of quantum information from one encoding to another and to representations that are convenient, efficient, or required for desired manipulations.Type: GrantFiled: April 30, 2004Date of Patent: November 11, 2008Assignee: Hewlett-Packard Development Company, L.P.Inventors: Raymond G. Beausoleil, Jr., William J. Munro, Timothy P. Spiller, Kae Nemoto
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Patent number: 7426444Abstract: Various embodiments of the present invention are directed to methods for determining a phase shift acquired by an entangled N-qubit system represented by a NOON state. In one embodiment, a probe electromagnetic field is coupled with each qubit system. The phase shift acquired by the qubit systems is transferred to the probe electromagnetic field by transforming each qubit-system state into a linear superposition of qubit basis states. An intensity measurement is performed on the probe electromagnetic field in order to obtain a corresponding measurement result. A counter associated with a measurement-result interval is incremented, based on the measurement result falling within the measurement-result interval. A frequency distribution is produced by normalizing the counter associated with each measurement-result interval for a number of trials.Type: GrantFiled: April 19, 2006Date of Patent: September 16, 2008Assignee: Hewlett-Packard Development Company, L.P.Inventors: Raymond G. Beausoleil, William J. Munro, Timothy P. Spiller, Pieter Kok, Sean D. Barrett, Kae Nemoto
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Publication number: 20070250280Abstract: Various embodiments of the present invention are directed to methods for determining a phase shift acquired by an entangled N-qubit system represented by a NOON state. In one embodiment, a probe electromagnetic field is coupled with each qubit system. The phase shift acquired by the qubit systems is transferred to the probe electromagnetic field by transforming each qubit-system state into a linear superposition of qubit basis states. An intensity measurement is performed on the probe electromagnetic field in order to obtain a corresponding measurement result. A counter associated with a measurement-result interval is incremented, based on the measurement result falling within the measurement-result interval. A frequency distribution is produced by normalizing the counter associated with each measurement-result interval for a number of trials.Type: ApplicationFiled: April 19, 2006Publication date: October 25, 2007Inventors: Raymond Beausoleil, William Munro, Timothy Spiller, Pieter Kok, Sean Barrett, Kae Nemoto
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Publication number: 20070215862Abstract: Various embodiments of the present invention are directed to methods for generating an entangled state of qubits. In one embodiment of the present invention, a method for preparing an entangled state of qubits comprises providing a probe and N non-interacting qubits, each qubit comprises a linear superposition of two basis states. The probe is transmitted into an interaction region that separately couples the probe to each of the qubits and produces a number of different probes. A linear superposition of states is output from the interaction region, each state in the linear superposition of states comprises a tensor product of entangled basis states and one of the different probes. The linear superposition of states is projected into one of the entangled states by measuring the state of the probe.Type: ApplicationFiled: January 30, 2006Publication date: September 20, 2007Inventors: Raymond Beausoleil, William Munro, Timothy Spillar, Pieter Kok, Sean Barrett, Kae Nemoto
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Publication number: 20070145271Abstract: Structures and methods allow: transfer of quantum information represented using the states of light to a representation using the states of matter systems; transfer of quantum information represented by the states of matter systems to a representation using the states of light; and error resistant encoding of quantum information using entangled states of matter and light to minimize errors.Type: ApplicationFiled: October 17, 2005Publication date: June 28, 2007Inventors: Raymond Beausoleil, William Munro, Timothy Spiller, Kae Nemoto
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Patent number: 7133173Abstract: Nonlinear electromagnetic elements can efficiently implement quantum information processing tasks such as controlled phase shifts, non-demolition state detection, quantum subspace projections, non-demolition Bell state analysis, heralded state preparation, quantum non-demolition encoding, and fundamental quantum gate operations. Direct use of electromagnetic non-linearity can amplify small phase shifts and use feed forward systems in a near deterministic manner with high operating efficiency. Measurements using homodyne detectors can cause near deterministic projection of input states on a Hilbert subspace identified by the measurement results. Feed forward operation can then alter the projected state if desired to achieve a desired output state with near 100% efficiency.Type: GrantFiled: July 26, 2004Date of Patent: November 7, 2006Assignee: Hewlett-Packard Development Company, L.P.Inventors: Raymond G. Beausoleil, Jr., William J. Munro, Timothy P. Spiller, Sean D. Barrett, Pieter Kok, Kae Nemoto
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Patent number: 7038188Abstract: A device capable of efficiently detecting a single-photon signal preserves a photon characteristic such as polarization or angular momentum. The device can include a beam splitter that splits an input photon state into modes that are distinguished by states of a characteristic of signal photons in the input photon state, a non-destructive measurement system capable of measuring a total number of photons in the modes without identifying a photon number for any individual one of the modes; and a beam combiner positioned to combine the modes after output from the non-destructive detection system.Type: GrantFiled: April 29, 2004Date of Patent: May 2, 2006Assignee: Hewlett-Packard Development Company, LP.Inventors: Raymond G. Beausoleil, Jr., William J. Munro, Timothy P. Spiller, Kae Nemoto, Sean D. Barrett
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Patent number: 7002133Abstract: A device capable of efficiently detecting a single-photon signal includes a matter system, sources of a first beam and a second beam, and a measurement system. The matter system has a first energy level and a second energy level such that a signal photon couples to a transition between the first energy level and the second energy level. The first beam contains photons that couple to a transition between the second energy level and a third energy level of the matter system, and the second beam contains photons that couple to a transition between the third energy level and a fourth energy level of the matter system. The measurement system measures a change in the first or second beam to detect the absence, the presence, or the number of the photons in the signal.Type: GrantFiled: October 3, 2003Date of Patent: February 21, 2006Assignee: Hewlett-Packard Development Company, L.P.Inventors: Raymond G. Beausoleil, William J. Munro, Timothy P. Spiller, Kae Nemoto, Sean D. Barrett