Abstract: The purpose of the present invention is to provide an optical computer having high scalability and capable of reducing noise. This optical computer is characterized by including: an input layer which accepts an input signal as a computer; a reservoir layer which responds to a signal input from the input layer, and in which using a plurality of degenerate optical parametric oscillator (DOPO) pulses of a DOPO that are generated by an optical phase-sensitive amplifier (PSA) based on pump light as nodes, a connection relation between the nodes is determined by a measurement feedback method or a method equivalent to the measurement feedback method; and an output layer which outputs an output signal based on the respective responses of the plurality of DOPO pulses to the input signal from the reservoir layer.

Abstract: In an Ising model calculation device for computing a generalized Ising model expressed by a Hamiltonian having a magnetic field term, the magnetic field term is applied to spins simulated by state monitoring light pulses, and a response of the obtained light pulses is determined by fitting to perform state monitoring during application of a magnetic field term.

Abstract: The present invention provides an optical phase synchronization method characterized by involving applying a small phase modulation signal (dither signal) to local oscillator light, acquiring an error signal that is dependent on a phase shift, and controlling the phase shift. The present invention further provides an optical phase synchronization method characterized by involving inducing a specific phase pattern in dummy pulses in an optical resonator using injection light, applying phase modulation to the local oscillator light, and thereby acquiring a part of the measurement result of the dummy pulses as the error signal. The present invention is further characterized by arranging calculation pulses and phase synchronization dummy pulses in a distributed manner (for example, alternately) and increasing a pulse width using a narrow band electrical filter.

Abstract: In order to address an issue that an unsolved problem is caused in a conventional coherent Ising machine in which a term, which expresses a magnetic field at each site, is not able to be implemented, the present invention provides an Ising model calculation device comprising a push-pull-type optical modulator in which a role corresponding to “a local magnetic field” can be implemented by adjusting an operation point. The calculation device of the present disclosure is characterized by implementing an item, which expresses a magnetic field, at each site by adding, to the conventional coherent Ising machine, a function for simulating the magnetic field item. Specifically, light having the amplitude of a predetermined sign is input in the conventional coherent Ising machine by dislocating an operation point of the push-pull-type optical modulator.

Abstract: An XY model calculation apparatus of the present disclosure includes a resonator unit that amplifies a plurality of optical pulses, a measurement unit that measures phases and amplitudes of the plurality of optical pulses to obtain a measurement result, and a feedback configuration that calculates and feeds back an interaction related to a certain optical pulse of the plurality of optical pulses by using a coupling coefficient of an Ising model in response to the measurement result. The feedback configuration is configured to perform a feedback input of a correlation to be determined by a coupling coefficient of two optical pulses of the plurality of optical pulses and is configured so that only one component of pulsed light is to be measured.

Abstract: A quantum random number generator is provided that can generate more secure random numbers in consideration of at least one of imperfection of quantum bits or imperfection of a projective measurement equipment. In this generator, the functional configuration of a random number extractor differs from a conventional configuration, and the random number extractor acquires a probability distribution of measurement expectation values from information of a random number sequence for measurement basis selection used in the equipment, and at least one of information of imperfection of the equipment measured in advance, or information of imperfection of a quantum bit generator. Then, an estimation probability is calculated by using the probability distribution of the measurement expectation values, and a measurement result in a binary bit string output from the equipment is compressed by the calculated estimation probability to extract a secure random number.

Abstract: The present invention provides an optical phase synchronization method characterized by involving applying a small phase modulation signal (dither signal) to local oscillator light, acquiring an error signal that is dependent on a phase shift, and controlling the phase shift. The present invention further provides an optical phase synchronization method characterized by involving inducing a specific phase pattern in dummy pulses in an optical resonator using injection light, applying phase modulation to the local oscillator light, and thereby acquiring a part of the measurement result of the dummy pulses as the error signal. The present invention is further characterized by arranging calculation pulses and phase synchronization dummy pulses in a distributed manner (for example, alternately) and increasing a pulse width using a narrow band electrical filter.

Abstract: A Potts model computing device capable of computing a Potts problem that is a multivalued spin problem are described herein. The Potts model computing device includes: an Ising model computing device; a computation result storage and determination unit configured to store a value of a spin of the Ising model obtained in a case where a coupling coefficient is set in the Ising model computing device and to determine whether a computation is finished; and a coupling coefficient overwriting unit configured to update a coupling coefficient generated based on the stored value of the spin to the Ising model computing device. According to a value of a set of spins obtained as a computation result corresponding to a coupling coefficient set for an m-th time in the Ising model computing device, the coupling coefficient overwriting unit generates again a coupling coefficient to be set for an (m+1)-th iterative computation.

Abstract: The Ising model calculation device selects a solution having a consistent quality from among solutions obtained through the calculations with the evaluation index of a calculation accuracy. A coupling coefficient obtained by combining the Ising model coupling coefficient corresponding to a problem for which a solution should be calculated with the Ising model coupling coefficient corresponding to the check problem is set as a coupling coefficient used to calculate the interaction. With regard to a calculation value corresponding to the check spin among the calculation values using a plurality of light pulses, the compatibility as the solution of the check problem is judged. When the judgement result shows the compatibility as the solution of the check problem, a calculation value other than the calculation values corresponding to the check spin among the resultant calculation values is outputted as a solution to the problem for which a solution should be calculated.

Abstract: To provide a spiking neuron apparatus able to efficiently implement a simulation of a spiking neuron. A spiking neuron apparatus using a coherent Ising machine, the coherent Ising machine including: a resonator unit for amplifying a plurality of optical pulses; a measurement unit for measuring phases and amplitudes of the optical pulses to obtain a measurement result; and a feedback configuration for computing and feeding back an interaction related to a certain optical pulse using a coupling coefficient of Ising Model on the basis of the measurement result, the feedback configuration feedback inputting correlation determined by two coupling coefficients with opposite signs to two predetermined optical pulses of the optical pulses, the spiking neuron apparatus simulating a state of a spiking neuron using one of values of two optical pulses finally obtained by the measurement unit.

Abstract: The Ising model calculation device selects a solution having a consistent quality from among solutions obtained through the calculations with the evaluation index of a calculation accuracy. A coupling coefficient obtained by combining the Ising model coupling coefficient corresponding to a problem for which a solution should be calculated with the Ising model coupling coefficient corresponding to the check problem is set as a coupling coefficient used to calculate the interaction. With regard to a calculation value corresponding to the check spin among the calculation values using a plurality of light pulses, the compatibility as the solution of the check problem is judged. When the judgement result shows the compatibility as the solution of the check problem, a calculation value other than the calculation values corresponding to the check spin among the resultant calculation values is outputted as a solution to the problem for which a solution should be calculated.

Abstract: A Potts model computing device capable of computing a Potts problem that is a multivalued spin problem are described herein. The Potts model computing device includes: an Ising model computing device; a computation result storage and determination unit configured to store a value of a spin of the Ising model obtained in a case where a coupling coefficient is set in the Ising model computing device and to determine whether a computation is finished; and a coupling coefficient overwriting unit configured to update a coupling coefficient generated based on the stored value of the spin to the Ising model computing device. According to a value of a set of spins obtained as a computation result corresponding to a coupling coefficient set for an m-th time in the Ising model computing device, the coupling coefficient overwriting unit generates again a coupling coefficient to be set for an (m+1)-th iterative computation.

Abstract: A parametric oscillator oscillates a plurality of pseudo spin pulses SPi having mutually an identical oscillation frequency by using parametric oscillation, an interaction implementing unit performs feedback implementation of a magnitude and a sign of interaction related to each pseudo spin pulse SPi (the proportionality coefficient ?i+?Jij?j+?Kijk?j?k with respect to ?i) by using a tentative measurement result of oscillation phases ?i(tentative) of the plurality of pseudo spin pulses SPi, and a pseudo spin measuring unit measures the pseudo spins ?i of the plurality of pseudo spin pulses SPi, based on a final measurement result of oscillation phases ?i(steady) of the plurality of pseudo spin pulses SPi.

Abstract: In an Ising spin measuring step, measurement is suspended after one set of measurement of all Ising spins {?i} is completed before another set of measurement of all Ising spins {?i} is restarted. In an Ising interaction computing step, all Ising interactions relating to all the Ising spins ?i can be computed with a sufficient time margin on the basis of most recent measurement of Ising spins ?i, after one set of measurement of all the Ising spins {?i} is completed before another set of measurement of all the Ising spins {?i} is restarted by the Ising spin measuring step.

Abstract: In the present invention, a parametric oscillator 1 oscillates a plurality of pseudo spin pulses SPi having mutually an identical oscillation frequency by using parametric oscillation, an interaction implementing unit 5 performs feedback implementation of a magnitude and a sign of interaction related to each pseudo spin pulse SPi (the proportionality coefficient ?i+?Jij?j+?Kijk?j?k with respect to ?i) by using a tentative measurement result of oscillation phases ?i (tentative) of the plurality of pseudo spin pulses SPi, and a pseudo spin measuring unit 6 measures the pseudo spins ?i of the plurality of pseudo spin pulses SPi, based on a final measurement result of oscillation phases ?i (steady) of the plurality of pseudo spin pulses SPi.

Abstract: In an Ising spin measuring step, measurement is suspended after one set of measurement of all Ising spins {?i} is completed before another set of measurement of all Ising spins {?i} is restarted. In an Ising interaction computing step, all Ising interactions relating to all the Ising spins ?i can be computed with a sufficient time margin on the basis of most recent measurement of Ising spins ?i, after one set of measurement of all the Ising spins {?i} is completed before another set of measurement of all the Ising spins {?i} is restarted by the Ising spin measuring step.

Abstract: A parametric oscillator oscillates a plurality of pseudo spin pulses SPi having mutually an identical oscillation frequency by using parametric oscillation, an interaction implementing unit performs feedback implementation of a magnitude and a sign of interaction related to each pseudo spin pulse SPi (the proportionality coefficient ?i+?Jij?j+?Kijk?j?k with respect to ?i) by using a tentative measurement result of oscillation phases ?i(tentative) of the plurality of pseudo spin pulses SPi, and a pseudo spin measuring unit measures the pseudo spins ?i of the plurality of pseudo spin pulses SPi, based on a final measurement result of oscillation phases ?i(steady) of the plurality of pseudo spin pulses SPi.

Abstract: Differential phase shift (DPS) quantum key distribution (QKD) is provided, where the average number of photons per transmitted pulse is predetermined such that the secure key generation rate is maximal or nearly maximal, given other system parameters. These parameters include detector quantum efficiency, channel transmittance and pulse spacing (or clock rate). Additional system parameters that can optionally be included in the optimization include baseline error rate, sifted key error rate, detector dead time, detector dark count rate, and error correction algorithm performance factor. The security analysis leading to these results is based on consideration of a hybrid beam splitter and intercept-resend attack.

Abstract: Differential phase shift (DPS) quantum key distribution (QKD) is provided, where the average number of photons per transmitted pulse is predetermined such that the secure key generation rate is maximal or nearly maximal, given other system parameters. These parameters include detector quantum efficiency, channel transmittance and pulse spacing (or clock rate). Additional system parameters that can optionally be included in the optimization include baseline error rate, sifted key error rate, detector dead time, detector dark count rate, and error correction algorithm performance factor. The security analysis leading to these results is based on consideration of a hybrid beam splitter and intercept-resend attack.