Patent application number | Description | Published |
20080231837 | QUANTUM BIT READING DEVICE AND METHOD - An apparatus includes a material in a resonator and containing systems, each of the systems having five energy states, a unit generating first and second pulse that resonate in a second transition and a third transition, respectively, a unit controlling the first and second pulse to make the first and second pulse temporally overlap each other to obtain third light, a unit emitting the third light to each system, a unit generating observation light to be coupled to the resonator mode, a unit introducing the observation light to the resonator from an outside thereof, a unit reading one of quantum bits by measuring an intensity of one of reflected light and transmitted light of the observation light, a unit controlling the first and second pulse to make the first and second pulse temporally overlap each other to obtain fourth light, and a unit emitting the fourth light to each system. | 09-25-2008 |
20080232814 | QUANTUM COMMUNICATION APPARATUS AND QUANTUM COMMUNICATION METHOD - A quantum communication apparatus is used in operations to generate entanglement between the two physical system ensembles and operations to extend the distance between entangled ensembles by connecting pairs of entangled ensembles. The apparatus uses only passive elements without any actuating parts, active devices having no mechanically actuating parts, such as an electro-optical device capable of ultrahigh-speed operation, and a laser source capable of generating high-speed pulse trains or a continuous wave laser source. The apparatus can rapidly execute light irradiation necessary for entanglement generation and connection, and detection of a generated photon at the needed sites within a decoherence time of the physical system. | 09-25-2008 |
20090009165 | QUANTUM INFORMATION PROCESSING DEVICE AND METHOD - Quantum information processing device includes resonator incorporating material containing physical systems, each of physical systems having at least four energy states, transition between two energy states of at least four energy states, and transition energy between at least two energy states of at least four energy states, at least four energy states being non-degenerate when magnetic field fails to be applied to physical systems, transition resonating in resonator mode that is in common between physical systems, each of at least four energy states representing a quantum bit, transition energy being shifted when magnetic field is applied to physical systems, and magnetic-field application unit configured to apply magnetic field having direction and intensity to material, to eliminate linear transition energy shift between two energy states included in physical systems, each of two energy states included in physical systems being with excluding two energy states resonating in resonator mode. | 01-08-2009 |
20090030962 | QUANTUM COMPUTING METHOD AND QUANTUM COMPUTER - An (N+1) number of physical systems each having five energy levels |0>, |1>, |2>, |3>, and |4>, a qubit being expressed by |0> and |1>, are provided in an optical cavity having a cavity mode resonant with |2>-|3>, such that an N number of control systems and a target system are prepared. The target system is irradiated with light pulses resonant with |0>-|4>, |1>-|4>, and |2>-|4> to change a superposed state |c> to |2>. All of the physical systems are irradiated with light pulses resonant with |0>-|3> and |1>-|3>, and a phase of the light pulse resonant with the target system is shifted by a specific value dependent on a unitary transformation U. The target system is irradiated with light pulses resonant with |0>-|4>, |1>-|4>, and |2>-|4>, with a phase difference between them being set to a specific value dependent on the unitary transformation U, to return |2> to |c>. | 01-29-2009 |
20090084991 | SINGLE-PHOTON GENERATION APPARATUS AND QUANTUM BIT READING APPARATUS AND METHOD - A method of generating a single photon, includes preparing an optical resonator including a resonator mode of a resonance angular frequency ω | 04-02-2009 |
20090091812 | QUANTUM COMPUTER AND QUANTUM COMPUTATION METHOD - A quantum computer includes physical systems, included in an optical resonator, having at least four energy states, and in which letting |0>, |1>, |3>, and |2> be the four energy states, an energy of |2> is higher than energies of |0>, |1>, and |3>, a transition frequency of a |0>−|2> transition is equal to the resonance frequency, and |0> and |1> express a quantum bit, a first source emitting light that resonates with the optical resonator, a second source irradiating specific physical systems of the physical systems with light that couples |3> and |2>, a light detector detecting a photon emitted from the optical resonator, and a controller controlling the first source to irradiate the optical resonator with light and controlling the light detector to perform light detection during irradiation of the light that couples |3> and |2> from the second source to the specific physical systems. | 04-09-2009 |
20090153952 | OPTICAL RESONATOR - An optical resonator includes a master resonator configured to resonate an electromagnetic wave, one structure or a pair of structures adjacent to each other, each of which is arranged at a position that overlaps one of resonance modes of the master resonator, is made up of a material in which a real part of a permittivity assumes a negative value, and an absolute value of the real part is larger than an absolute value of an imaginary part of the permittivity, and has a size which makes scattering that the electromagnetic wave suffers be Rayleigh scattering, and one or a plurality of particles, each of which is laid out near the structure by a distance smaller than the size of the structure. | 06-18-2009 |
20090213444 | QUANTUM COMPUTING METHOD AND QUANTUM COMPUTER - A quantum bit computation method includes operating a two-quantum-bit gate on quantum bits of a first physical system and a second physical system, second energy states of second physical systems except for the first physical system and the second physical system do not change, three energy states being represented by | | 08-27-2009 |
20100044600 | QUANTUM COMPUTER AND QUANTUM COMPUTING METHOD - A quantum computer includes a unit including thin films A, B and C each containing a physical-system group A, B and C formed of physical systems A, B and C, the films A, B and C being alternately stacked in an order of A, B, C, A, . . . , each of the systems A, B and C having three-different-energy states | | 02-25-2010 |
20100088488 | QUANTUM GATE METHOD AND APPARATUS - A method includes causing a common-resonator mode resonating with a transition between |2> | 04-08-2010 |
20120008182 | QUANTUM COMPUTING METHOD AND QUANTUM COMPUTER - A quantum bit computation method includes operating a two-quantum-bit gate on quantum bits of a first physical system and a second physical system, second energy states of second physical systems except for the first physical system and the second physical system do not change, three energy states being represented by |0>, |1> and |3>, the two energy states being represented by |2> and |4>, energies of |2> and |4> being higher than energies of |0>, |1> and |3>, a transition frequency between |3> and |2> being equal to the resonance frequency, |0> and |1> representing quantum bits, flipping quantum bits of first physical systems after operating the two-quantum-bit gate, executing no operations by a time equal to a time for operating the two-quantum-bit gate, after flipping the quantum bits, and again flipping the quantum bits of the first physical systems after executing no operations. | 01-12-2012 |
20120170091 | QUANTUM COMPUTER AND QUANTUM MEMORY - According to one embodiment, a quantum computer includes a crystal, an optical resonator, and a light source. A host crystal included in the crystal satisfying three conditions a first condition that maximum phonon energy of the host crystal is low, and so that a homogenous broadening of a | 07-05-2012 |
20130070329 | ACOUSTO-OPTIC MODULATOR - According to one embodiment, an acousto-optic modulator includes an acousto-optic medium and a piezoelectric transducer. The acousto-optic medium has a configuration of a hexahedron. The acousto-optic medium has surfaces D, E, F, G and H. The piezoelectric transducer is provided on a surface C of the acousto-optic medium. The surface D opposes the surface C and has respective four sides shared by the surfaces E, F, G and H. Four angles defined between the surface D and the surfaces E, F, G and H each is other than 90°. At least one of eight angles defined between each pair of the surfaces C, E, F, G and H is other than 90°. The each pair has one shared side. | 03-21-2013 |
20140289583 | DECODING APPARATUS, DECODING METHOD, AND DECODING PROGRAM - According to one embodiment, a decoding apparatus includes first and second acquisition units, a holding unit, a calculation unit, and a decision unit. The first acquisition unit acquires first measurement values of measurements performed to measure an eigenvalue of an encoded Z operator to a first encoded qubit of the two encoded qubits. The second acquisition unit acquires second measurement values of measurements performed to measure an eigenvalue of an encoded X operator to a second encoded qubit of the two encoded qubits. The holding unit holds error probabilities for the first measurement values and the second measurement values. The calculation unit calculates probabilities for measurement values of an encoded Bell measurement by using the first measurement values, the second measurement values, and the error probabilities. The decision unit decides measurement values of the encoded Bell measurement, based on the calculated probabilities. | 09-25-2014 |