公开(公告)号：US20240027870A1

公开(公告)日：2024-01-25

申请号：US18245430

申请日：2020-10-01

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Yuya Yonezu ,  Atsushi Ishizawa ,  Hidetaka Nishi ,  Tai Tsuchizawa ,  Nobuyuki Matsuda ,  Rai Takahashi ,  Koji Yamada

IPC: G02F1/35 ,  G01N21/41 ,  G02F1/365

CPC classification number: G02F1/3526 ,  G01N21/41 ,  G02F1/365

Abstract: An optical nonlinearity measurement method according to the present disclosure utilizes photon pair generation through a spontaneous four-wave mixing process, to observe photon pairs using an optical waveguide loaded with a two-dimensional material. Compared with the Z-scan method, the influence of free carriers on nonlinear refractive indexes is only indirect. With a parameter being the length of the attached two-dimensional material in the optical waveguide direction, a theoretical value of the coincidence rate of the photon pairs based on the coupled wave equation is fitted to a measured value of the coincidence rate of the photon pairs. For the coincidence rate of the photon pairs, the theoretical value based on the coupled wave equation is fitted to the measured value in a state reflecting the structure of the optical waveguide loaded with the two-dimensional material, and nonlinear coefficients γ1 and γ2 at that time are obtained.

公开(公告)号：US20240394328A1

公开(公告)日：2024-11-28

申请号：US18681314

申请日：2021-08-25

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Hiroki Takesue ,  Takahiro Inagaki ,  Toshimori Honjo ,  Kensuke Inaba ,  Yasuhiro Yamada ,  Takuya Ikuta ,  Yuya Yonezu

IPC: G06F17/11

Abstract: A calculation device that simulates spin states of a finite-temperature Ising model by combining characteristics of a coherent Ising machine and an electronic calculator is provided. The calculation device includes a coherent Ising machine including a sampling unit that samples a spin state, the sampling unit introducing a check spin for extracting a sample in addition to a target spin for solving a target problem for which a solution of the Ising model is to be obtained, and an electronic calculator including a temperature estimation unit that calculates a temperature or an inverse temperature of a sample in a spin state extracted by the sampling unit, and an integration processing unit that integrates a plurality of samples and performs statistical processing.

公开(公告)号：US20240403686A1

公开(公告)日：2024-12-05

申请号：US18697855

申请日：2021-10-06

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Takuya Ikuta ,  Seiseki Akibue ,  Yuya Yonezu ,  Toshimori Honjo ,  Hiroki Takesue

IPC: G06N10/60

Abstract: Disclosed are a high-dimensional quantum state generation device and a state measurement device using the mutually unbiased bases utilizing a finite field. The mutually unbiased bases in a high-dimensional quantum state are realized by a calculation method utilizing the finite field. A device is disclosed that utilizes mutually unbiased bases in the time-bin quantum state of light, frequency-bin quantum state and other modes of light, as the high-dimensional quantum state utilizing the finite field. The generation device and the measurement device are realized by the phase modulator and units equivalent to the matrix transformation operation, respectively. The measurement device includes a phase modulation unit corresponding to a diagonal unitary transform to a computational basis which is the first unit on the front stage side, and a high-dimensional Hadamard transform measurement unit or a Fourier transform measurement unit which is the second unit.