2018 Fiscal Year Final Research Report

Realization and Application of Large-scale Quantum Entangled States Using Photonic Quantum Circuits

Research Project

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Project/Area Number	26220712
Research Category	Grant-in-Aid for Scientific Research (S)
Allocation Type	Single-year Grants
Research Field	Atomic/Molecular/Quantum electronics
Research Institution	Kyoto University
Principal Investigator	Takeuchi Shigeki 京都大学, 工学研究科, 教授 (80321959)
Co-Investigator(Kenkyū-buntansha)	横山士吉九州大学, 先導物質化学研究所, 教授 (00359100) Hofmann Holger・F 広島大学, 先端物質科学研究科, 准教授 (90379909)
Research Collaborator	OKAMOTO ryo FUJIWARA masazumi TAKASHIMA hideaki
Project Period (FY)	2014-05-30 – 2019-03-31
Keywords	量子コンピュータ / ナノフォトニクス / 光導波路 / 光子 / 量子計測 / 量子センシング
Outline of Final Research Achievements	In order to realize large-scale entangled state, we have successfully demonstrated the heralded single photon with suppressed excess noise photons and the serial-parallel conversion of heralded single photons. Furthermore, we proposed and demonstrated a method to verify the large-scale entangled state much more simply than conventional methods. In addition, the world's first "quantum shutter" and "quantum controlled SWAP gate operation" have been realized using photonic quantum circuits. For the on-chip photonic circuit, we realized high-Q ring resonators and also observed photon pair generation. Furthermore, we realized broadband modulation in organic-inorganic hybrid devices. And we also realized high-quality nano-fiber Bragg cavity making full use of nano-scale microfabrication, and also realized hybrid single photon sources using various single light emitters.
Free Research Field	量子工学、量子情報科学
Academic Significance and Societal Importance of the Research Achievements	量子力学の基本的な原理を、情報通信・処理に応用する、量子情報科学が急速に発展している。その量子情報の担体として光子は、優れた制御性や、量子状態を保ったまま伝送が可能という特徴を持つ。これらの光子を効率よく生成し、多数の光子の量子相関を制御することで、従来の光計測の感度限界を超え、また量子通信や量子コンピューティングの応用が期待されている。本研究では、そのための様々な基盤的技術が開拓された。また、新たな光センシング応用など、当初予測を超える成果も得られた。