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Direct Observation of Broadband Nonclassical States in a Room-temperature Light-matter Interface

July 31, 2018      Author: Dou Jianpeng

On July 20, npj Quantum Information (impact factor 9.206), Nature Partner Journal, published the latest research result of Jin Xianmin's team, titled "Direct Observation of Broadband Nonclassical States in a Room-temperature Light-matter Interface". The paper presents a direct observation of broadband nonclassical states in a room-temperature light-matter interface, where the atoms can also be controlled to store and interfere with photons. The paper is of great significance for building scalable quantum information networks.

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The research team expresses gratitude for the support from key project of the Shanghai Science and Technology Committee (STCSM) and key research project of National Natural Science Foundation. They are also grateful for the great support of the Recruitment Program for Young Professionals,the Organization Department of the Central Committee of the CPC,National Key R&D Program of China and Shanghai Municipal Education Commission.

Abstract: Nonclassical state is an essential resource for quantum-enhanced communication, computing and metrology to outperform their classical counterpart. The nonclassical states that can operate at high bandwidth and room temperature while being compatible with quantum memory are highly desirable to enable the scalability of quantum technologies. Here, we present a direct observation of broadband nonclassical states in a room-temperature light-matter interface, where the atoms can also be controlled to store and interfere with photons. With a single coupling pulse and far off-resonance configuration, we are able to induce a multi-field interference between light and atoms to create the desired nonclassical states by spectrally selecting the two correlated photons out of seven possible emissions. We explicitly confirm the nonclassicality by observing a cross correlation up to 17 and a violation of Cauchy-Schwarz inequality with 568 standard deviations. Our results demonstrate the potential of a state-built-in, broadband and room-temperature light-matter interface for scalable quantum information networks.

 

Translated by Chen Wanrong  Reviewed by Wang Bingyu