ツジノ　ケンジ   TSUJINO Kenji   辻野　賢治    所属   統合教育学修センター 統合教育学修センター    職種   准教授
論文種別	原著
言語種別	英語
査読の有無	査読あり
表題	Quantum Receiver beyond the Standard Quantum Limit of Coherent Optical Communication
掲載誌名	正式名：Physical review letters 略　 称：Phys Rev Lett ISSNコード：00319007
巻・号・頁	106,pp.250503
著者・共著者	Kenji Tsujino†, Daiji Fukuda, Go Fujii, Shuichiro Inoue, Mikio Fujiwara, Masahiro Takeoka, Masahide Sasaki
担当区分	筆頭著者
発行年月	2011/06
概要	The most efficient modern optical communication is known as coherent communication, and its standard quantum limit is almost reachable with current technology. Though it has been predicted for a long time that this standard quantum limit could be overcome via quantum mechanically optimized receivers, such a performance has not been experimentally realized so far. Here we demonstrate the first unconditional evidence surpassing the standard quantum limit of coherent optical communication. We implement a quantum receiver with a simple linear optics configuration and achieve more than 90% of the total detection efficiency of the system. Such an efficient quantum receiver will provide a new way of extending the distance of amplification-free channels, as well as of realizing quantum information protocols based on coherent states and the loophole-free test of quantum mechanics.