Abstract: The present invention aims at enabling a gate-type quantum computer to deal with actual problems. There is provided a quantum computer including: a quantum register holding qubits, a control gate performing an operation on the quantum register, and a readout unit observing a state of the quantum register; and the quantum computer repeating longitudinal relaxation to the ground state by gradually changing Hamiltonian H(t) for a predetermined time, wherein the unitary operation determined by the Hamiltonian H(t) at each time is performed with the control gate for a time of about a longitudinal relaxation time, the quantum state is relaxed every time of about the longitudinal relaxation time, and the ground state prepared for an initial state is time-evolved to the ground state of the Hamiltonian which is defined as a problem.

Abstract: In a network system that connects a site 100 and a site 200 to each other via an open network and a closed network, an interface 131 performs control so that format information of confidential information can pass but the confidential information cannot pass therethrough between a computer 111 and a computer 121. An interface 231 performs control so that format information of confidential information can pass but the confidential information cannot pass therethrough between a computer 211 and a computer 221.

Abstract: A computing apparatus that does not need quantum coherence or a cryogenic cooling apparatus is provided for assignments that need an exhaustive search. A system is led to the ground state of the system where a problem is set, wherein spin sjz that is a variable follows a local effective magnetic field Bjz. The spin state at t=0 is initialized with a transverse field (in the x-direction). This corresponds to sjz=0. With time t, the magnetic field in the z-axis direction and the inter-spin interactions are gradually added, and finally the spin is directed to the +z- or ?z-direction. The z component of the spin sj is sjz=+1 or ?1. Here, in the process where the orientation of the spin sjz follows that of the effective magnetic field Bjz, correction parameters originating in quantum-mechanical effects are introduced and ground-state-maintaining performance is improved.

Abstract: A quantum computer includes: a module including quantum computation units having a plurality of qubits and selection units that cause the quantum computation units to perform parallel computations; and a read unit that acquires computation results of the quantum computation units of a plurality of modules and performs statistical averaging on the plurality of acquired computation results.

Abstract: A machine learning device includes a general arithmetic device that calculates data, and a reservoir arithmetic device including an input unit, an output unit, and one or more nodes. The reservoir arithmetic device performs a certain calculation on data and performs calculation in response to an input value input through an input unit using the dynamics of the nodes. Each node i outputs a measurement outcome zi(tk) at a time point tk. The general arithmetic device calculates y(tk)=?izi(tk)wi. In the calculation of y(tk), in addition to zi(tk) at the time point zi(tk), the term zi(tk?) at a time point tk? (tk??tk) is included. Thus, the calculation of y(tk) is performed by redundantly using zi(tk) at different time points, with the range of sum with respect to the subscript i being i=1, . . . qn, where q is redundancy.

Abstract: In a network system that connects a site 100 and a site 200 to each other via an open network and a closed network, an interface 131 performs control so that format information of confidential information can pass but the confidential information cannot pass therethrough between a computer 111 and a computer 121. An interface 231 performs control so that format information of confidential information can pass but the confidential information cannot pass therethrough between a computer 211 and a computer 221.

Abstract: Provided is a computer that does not need quantum coherence or a cryogenic cooling device for a problem to be solved that needs an exhaustive search and a computing program thereof. Spin sj as a variable is caused to follow a local effective magnetic field Bj to introduce a system to a ground state of a problem-setting system. The ground state is a solution. At t=0, the magnetic field Bj is applied in the x-axis direction at all sites and all spins sj are initialized to the x-axis direction. With the lapse of time t, a magnetic field in the z-axis direction and interspin interaction are gradually applied, spin becomes +z-direction or ?z-direction finally, and the z-component of spin sj becomes sjz=+1 or ?1. When the direction spin sj is caused to follow the direction of the effective magnetic field Bj, a relaxation term to keep the direction of spin sj is introduced to improve convergence of a solution.

Abstract: The objective of the invention is to provide an encoding method and a communication method wherein bit-error correction is easy for a authorized recipient but difficult for an unauthorized recipient. A transmission channel in which bit errors are moderately controlled is used to transmit/receive a random number sequence. A common key is shared between a transmitter and a receiver in advance; each bit value of the common key is connected with each slot of the random number sequence; the common key is used to divide the random number sequence into two or more random number series in accordance with the connection; and each random number series is independently encoded and parity check symbols are generated. The unit of the encoding is equal to or greater than the length of the common key so as to make a partial analysis by an unauthorized recipient impossible.

Abstract: An object of the invention is to provide a computing technology which can operate at room temperature and have a sufficient performance for combinatorial optimization problems that need an exhaustive search. In a local-field response method in which spins being variables respond to local effective magnetic fields, a time axis is discretely treated. When spins respond to effective magnetic fields, the effective magnetic fields are determined sequentially from the site having the small magnitude of a spin, and spins respond to the fields in order. When the sign of a spin is inverted, the information is reflected in the subsequent process of determining the effective magnetic fields for other sites. Thus, a many-body effect due to quantum entanglement is phenomenologically incorporated.

Abstract: A computing apparatus that does not need quantum coherence or a cryogenic cooling apparatus is provided for assignments that need an exhaustive search. A system is led to the ground state of the system where a problem is set, wherein spin sjz that is a variable follows a local effective magnetic field Bjz. The spin state at t=0 is initialized with a transverse field (in the x-direction). This corresponds to sjz=0. With time t, the magnetic field in the z-axis direction and the inter-spin interactions are gradually added, and finally the spin is directed to the +z- or ?z-direction. The z component of the spin sj is sjz=+1 or ?1. Here, in the process where the orientation of the spin sjz follows that of the effective magnetic field Bjz, correction parameters originating in quantum-mechanical effects are introduced and ground-state-maintaining performance is improved.

Abstract: A classical technique relying on thermodynamics is used, and spin sj, which is a variable, is made to follow a local effective magnetic field Bj to bring a system to a ground state of a problem-setting system. The ground state is a solution thereof. At t=0, the effective magnetic field Bj is applied rightward in all the sites, and all the spins sj are initialized rightward. The magnetic field in the z axis direction and the interaction between spins are gradually applied with time t, which finally brings the spins in the +z direction or the ?z direction, and the z components of the spins sj become sjz=+1 or ?1. In addition, correction parameters originating from quantum mechanical effects are introduced when the direction of the spin sj is made to follow the direction of the effective magnetic field Bj so as to improve calculation performance.

Abstract: Provided is a computer that does not need quantum coherence or a cryogenic cooling device for a problem to be solved that needs an exhaustive search and a computing program thereof. Spin sj as a variable is caused to follow a local effective magnetic field Bj to introduce a system to a ground state of a problem-setting system. The ground state is a solution. At t=0, the magnetic field Bj is applied in the x-axis direction at all sites and all spins sj are initialized to the x-axis direction. With the lapse of time t, a magnetic field in the z-axis direction and interspin interaction are gradually applied, spin becomes +z-direction or ?z-direction finally, and the z-component of spin sj becomes sjz=+1 or ?1. When the direction spin sj is caused to follow the direction of the effective magnetic field Bj, a relaxation term to keep the direction of spin sj is introduced to improve convergence of a solution.

Abstract: It is an object of the present invention to provide a device which can be easily manufactured and obtain a ground state of an arbitrary Ising model. A semiconductor device includes a first memory cell and a second memory cell that interacts with the first memory cell, in which storage content of the first memory cell and the second memory cell is stochastically inverted. The storage content is stochastically inverted by dropping threshold voltages of the first memory cell and the second memory cell. The threshold voltages of the first and second memory cells are dropping by controlling substrate biases, power voltages, or trip points of the first and second memory cells.

Abstract: A classical technique relying on thermodynamics is used, and spin sj, which is a variable, is made to follow a local effective magnetic field Bj to bring a system to a ground state of a problem-setting system. The ground state is a solution thereof. At t=0, the effective magnetic field Bj is applied rightward in all the sites, and all the spins sj are initialized rightward. The magnetic field in the z axis direction and the interaction between spins are gradually applied with time t, which finally brings the spins in the +z direction or the ?z direction, and the z components of the spins sj become sjz=+1 or ?1. In addition, correction parameters originating from quantum mechanical effects are introduced when the direction of the spin sj is made to follow the direction of the effective magnetic field Bj so as to improve calculation performance.

Abstract: It is an object of the present invention to provide a device which can be easily manufactured and obtain a ground state of an arbitrary Ising model. A semiconductor device includes a first memory cell and a second memory cell that interacts with the first memory cell, in which storage content of the first memory cell and the second memory cell is stochastically inverted. The storage content is stochastically inverted by dropping threshold voltages of the first memory cell and the second memory cell. The threshold voltages of the first and second memory cells are dropping by controlling substrate biases, power voltages, or trip points of the first and second memory cells.

Abstract: The objective of the invention is to provide an encoding method and a communication method wherein bit-error correction is easy for a authorized recipient but difficult for an unauthorized recipient. A transmission channel in which bit errors are moderately controlled is used to transmit/receive a random number sequence. A common key is shared between a transmitter and a receiver in advance; each bit value of the common key is connected with each slot of the random number sequence; the common key is used to divide the random number sequence into two or more random number series in accordance with the connection; and each random number series is independently encoded and parity check symbols are generated. The unit of the encoding is equal to or greater than the length of the common key so as to make a partial analysis by an unauthorized recipient impossible.

Abstract: High-security communications against information leakage as well as high-speed communications are realized using present optical fiber networks. The methods are as follows: (1) A seed key is shared between a transmitter and a receiver in advance. Random numbers are transmitted using carrier light accompanied by fluctuations and bases that are decided by random numbers. The transmitter and receiver compare a shared basis that is determined by the seed key with the random basis, and decompose the random numbers superimposed on each bit into two sequences, based on whether the shared basis coincides with the random basis or not. Error correction is processed for each sequence in the receiver, and then the random numbers are shared between the transmitter and the receiver. (2) The amount of the random numbers shared between the transmitter and the receiver is reduced to secret capacity through privacy amplification, and the resultant random numbers are used as a secret key.

Abstract: Communications having high security against information leakage can be established in a current optical fiber network in the following manner. (1) A sender and a receiver share a seed key in advance, and then transmit and receive random numbers superimposed on carrier light accompanied with fluctuations, where transmission basis is determined by a random number. The sender and the receiver check a shared basis determined by the seed key with a random basis and employ only a random number signal superimposed on a slot for the shared basis that coincides with the random basis, and share the random numbers between the sender and the receiver. Here, since the carrier light has fluctuations, a bit error exists in the received signals. However, because of the seed key, a legitimate receiver can receive a signal with a bit error rate smaller than an eavesdropper.

Abstract: High-security communications against information leakage as well as high-speed communications are realized using present optical fiber networks. The methods are as follows: (1) A seed key is shared between a transmitter and a receiver in advance. Random numbers are transmitted using carrier light accompanied by fluctuations and bases that are decided by random numbers. The transmitter and receiver compare a shared basis that is determined by the seed key with the random basis, and decompose the random numbers superimposed on each bit into two sequences, based on whether the shared basis coincides with the random basis or not. Error correction is processed for each sequence in the receiver, and then the random numbers are shared between the transmitter and the receiver. (2) The amount of the random numbers shared between the transmitter and the receiver is reduced to secret capacity through privacy amplification, and the resultant random numbers are used as a secret key.

Abstract: Signals can be superimposed on optical phase even when low-coherency light is used, and a bit rate and a signal coding format similar to those used in ordinary optical communications can be used. A transmitter includes an asymmetric interferometer or an antisqueezed light generator to convert a train of single pulses into a train of dual pulses. A receiver also includes an asymmetric interferometer that provides the same delay time as that between the dual pulses. The receiver allows pulses originating in the same light source to interfere, so that signals can be superimposed on the phase even when a low-coherency light source is used. The delay time (optical path length difference) provided in the asymmetric interferometer is set to be longer than half the period of the pulses outputted from the optical pulse source.