Leland Stanford Junior University

Molex Corporation

The Whitaker Corporation

Japan Science and Technology Corporation

Inter-university Research Institute Corporation Research Organization of Information and Systems

Nippon Telegraph and Telephone Corporation

Other

Hewlett-packard Development Company, L.p.

Tetra Laval Holdings & Finance S.a.

Osaka University

Tyco Electronics Amp K.k.

Research Development Corporation of Japan

Ntt Corporation

Nishikawa Sangyo Co., Ltd.

Yoshihisa Yamamoto

Shoji Yamada

Shoko Utsunomiya

Hiroki Takesue

Shintaro Abe

Hiroshi Kojima

Charles Santori

Hideyuki Hirata

Masami Sasao

Edo Waks

Tomoo Yamada

Toshimori Honjo

Kenta Takata

Yoshihiro Takiguchi

Dehuan Huang

Kyo Inoue

Toshishige Yamada

Shudong Jiang

Susumu Machida

Matthew Pelton

Satoru Watanabe

Hiroshi Shirai

Robert L Byer

Jungsang Kim

William John Munro

Masanori Yagi

Kazushige Asakawa

Jelena Vuckovic

Takahiro Inagaki

Takashi Futatsugi

Kae Nemoto

Ikuo Enomoto

Francis Ho

Hiroyuki Obata

Shuhei Tamate

Alireza Marandi

Yoji Yoshimura

Oliver Benson

Fumiko Yamaguchi

Zhe Wang

Kai Yan

Jun Chen

Kai Wen

Kenji Takagi

Yoji Shimura

Koushiro Fukai

Hui Cao

Stanley Pau

Yoshitaka Haribara

Eleni Diamanti

Peter Van Loock

Koji Igarashi

In an Ising spin measuring step, measurement is suspended after one set of measurement of all Ising spins {&#x3c3;} is completed before another set of measurement of all Ising spins {&#x3c3;} is restarted. In an Ising interaction computing step, all Ising interactions relating to all the Ising spins &#x3c3;can be computed with a sufficient time margin on the basis of most recent measurement of Ising spins &#x3c3;, after one set of measurement of all the Ising spins {&#x3c3;} is completed before another set of measurement of all the Ising spins {&#x3c3;} is restarted by the Ising spin measuring step.

Ising model quantum computation device

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 &#x3bb;+&#x3a3;J&#x3c3;+&#x3a3;K&#x3c3;&#x3c3;with respect to &#x3c3;) by using a tentative measurement result of oscillation phases &#x3d5;(tentative) of the plurality of pseudo spin pulses SPi, and a pseudo spin measuring unit measures the pseudo spins &#x3c3;of the plurality of pseudo spin pulses SPi, based on a final measurement result of oscillation phases &#x3d5;(steady) of the plurality of pseudo spin pulses SPi.

Quantum computing device for Ising model, quantum parallel computing device for Ising model, and quantum computing method for Ising model

In one aspect, a computational machine includes an optical device configured to receive energy from an optical energy source and generate a number Nof optical signals, and a number Nof coupling devices, each of which controllably couples a plurality of the number Noptical signals. The coupling devices are individually controlled to simulate a computational problem. In another aspect, a computational machine includes a number Nof parametric oscillators and a number Nof coupling devices, each of which controllably couples a plurality of the number Nof parametric oscillators together. The coupling devices are individually controlled to simulate a computational problem.

Computation using a network of optical parametric oscillators

This computation device and method exponentially shortens a computation time of an NP-complete problem or the like mapped into an Ising model by exponentially shortening a computation time of the Ising mode. For each pair of a plurality of slave lasers, by controlling the intensity, the polarization, and the phase of light exchanged between two slave lasers using an attenuator and a wave plate, the magnitude and the sign of pseudo Ising interaction between two slave lasers are implemented. Then, after the plurality of slave lasers arrive at a steady state, by measuring the polarization of light generated by each slave laser with left-handed circular polarization and right-handed circular polarization used as bases, a pseudo spin of each slave laser is measured.

Ising model quantum computation device and Ising model quantum computation method

For each pair of a plurality of slave lasers B for which injection synchronization is performed by a master laser M, by controlling the intensity of light exchanged between two slave lasers B and an optical path length between the two slave lasers B using a slave-to-laser intensity control unit IA and an inter-slave laser optical path length control unit IP, the magnitude and the sign of pseudo ising interaction Jbetween the two slave lasers B are implemented. After the plurality of slave lasers B arrive at a steady state, by measuring relative values of the oscillation phases of the plurality of slave lasers B with respect to the oscillation phase of the master laser M by using an oscillation phase measuring unit PM, pseudo ising spins &#x3c3;of the plurality of slave lasers B are measured.

Quantum computer and quantum computing using ising model

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.

Differential phase shift keying quantum key distribution

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.

Quantum repeater

A system and method for quantum key distribution uses a regulated single-photon source to sequentially generate a first photon and a second photon separated by a time interval &#x394;t. The two photons are directed through a beam splitter that directs each photon to one of two transmission lines, which lead to two respective receivers. When one of the photons arrives at a receiver, it passes through an interferometer. One arm of the interferometer has a path length longer than the other arm by an amount equivalent to a photon time delay of &#x394;t. The photon is then detected in one of three time slots by one of two single-photon detectors associated with each of the two interferometer outputs. Due to quantum-mechanical entanglement in phase and time between the two photons, the receivers can determine a secret quantum key bit value from their measurements of the time slots in which the photons arrived, or of the detectors where the photons arrived.

Quantum key distribution system and method using regulated single-photon source

A micropost microcavity device has a maximum field intensity at the center of a high-index spacer as well as a small mode volume. The device has an approximately half-wavelength thick low-index spacer [sandwiched between two quarter wave stacks [. The low-index spacer has a high-index subspacer layer [positioned at its center. The subspacer layer has a thickness smaller than a quarter wavelength. As a result, the electric field intensity remains a maximum at the center of the spacer where the high-index subspacer is positioned. A quantum dot or other active region [may be embedded within the subspacer [. The microcavity devices provide, for example, single photon sources, single dot lasers, low-threshold quantum dot or quantum well lasers, or devices for strong coupling between a single quantum dot and the cavity field which can be used as components of photonic integrated circuits, quantum computers, quantum networks, or quantum cryptographic systems.

Half-wavelength micropost microcavity with electric field maximum in the high-refractive-index material

A device including a photon emitter, a light source, and a filter with a corresponding method for producing triggered single photons and triggered pairs of polarization-entangled photons are provided. The light source delivers a pulse to a photon emitter and generates pairs of electrons and holes to emit photons. The light source includes a mechanism to tune a pulse wavelength to an excited state-absorption resonance of the photon emitter. The light source could also include a device to selectively choose a polarization to create the pairs of electrons and holes of a particular spin. A filter isolates the last and single photon. Optionally, a micro-cavity is included to direct the emitted photons and couple to one or more optical elements. When the device or the method is used to produce triggered pairs of polarization-entangled photons, it works almost the same as for the single photons, except for modifications to the way the light source excites the photon emitter and how emission filtering is performed.

Quantum-dot triggered photon and triggered photon pair

Provided is a surface-mounted IC socket having a base housing and a gripping sheet. The base housing has a top surface and contacts. A slider moves over the top surface of the base housing and has an upper surface with a plurality of pin contact receiving holes arranged in the form of a matrix that receives pin contacts formed on an IC package that contact the contacts. Projecting parts having outer edges protrude from the upper surface. The gripping sheet has cuts corresponding to the projecting parts and is pasted on the upper surface such that the cuts correspond to the projecting parts.

IC socket and gripping sheet used in the same

A quantum-dot photon turnstile device is capable of producing a stream of regulated and directed single pairs of photons with opposite circular polarizations. This device operates by injecting pairs of electrons and holes, alternately, into a single quantum dot, where they combine to form photons. The device will efficiently and reliably produce a directed beam of such photons at regular time intervals. It will be able to operate at high frequency and at high temperature. Such a stream of regulated photon pairs will be useful in quantum cryptography, quantum computing, low-power optical communications, as a light standard, and in many other areas of technology and fundamental science.

Quantum-dot photon turnstile device

A quantum computer comprises a crystal lattice having storage atoms. The storage atoms have nuclear storage spins, and quantum bits are stored as orientations of the storage spins. A magnetic field is applied to the crystal, the magnetic field having a gradient on the order of 1T/&mgr;m. The gradient is generated by a micromagnet. The electrons of the crystal acquire a regular order, and the storage spins are initialized by inducing combined electron-nucleus transitions in the crystal, thereby transferring the electronic order to the storage spins. The storage spins are decoupled from each other by a decoupling magnetic field. Quantum logic operations are performed on the storage spins. Certain quantum logic operations require a modification of the decoupling field to recouple a plurality of the storage spins. Final polarizations of the storage spins are measured.

Crystal lattice quantum computer

A card connector provides for reliable grounding and, at the same time, makes it possible to simplify the mounting, maintenance and servicing operations. Card connector ( ) comprises a main body ( ) including a dielectric housing ( ) accommodating multiple electrical contacts ( ) and a grounding member ( ) that is fabricated separately from the main body ( ) and is secured thereto. The grounding member ( ) has tabs ( ) that electrically connect with an outer surface of a card inserted in the card connector ( ) and connecting sections ( ), the purpose of which is to electrically connect with electrical circuitry of a circuit board. The grounding member ( ) can be latchably attached to the main body ( ) that is mounted to the circuit board ( ), and if necessary, it can be removed, thus providing access to connecting sections ( ) of electrical contacts ( ).

Card connector having an improved grounding member

A compact ZIF type socket is provided having the durability to withstand numerous movements of the slider. The ZIF type IC socket consists of a base housing assembly that accommodates numerous contacts, and a cover housing assembly that can slide over the base housing assembly . The cover housing assembly is caused to move in relative terms by inserting a plate-form tool into tool insertion holes and respectively formed in a metal supporting plate on the side of the base housing assembly and a metal supporting plate on the side of the cover housing assembly , and rotating this tool . The action points of the tool insertion holes and contacted by the tool are formed as circular-arc-form projections and . Accordingly, the force of the tool can be transmitted to the base housing assembly and cover housing assembly without causing indentation or damage, etc., of the tool insertion holes and , so that a highly durable ZIF type socket can be obtained.

ZIF type socket

Growing community of inventors

Stanford, CA, United States of America

Yoshihisa Yamamoto