• Advanced Photonics
  • Vol. 3, Issue 6, 064002 (2021)
Xiaojiong Chen1、†, Zhaorong Fu1, Qihuang Gong1、2、3、4, and Jianwei Wang1、2、3、4、*
Author Affiliations
  • 1Peking University, School of Physics, State Key Laboratory for Mesoscopic Physics, Beijing, China
  • 2Peking University, Frontiers Science Center for Nano-Optoelectronics, Collaborative Innovation Center of Quantum Matter, Beijing, China
  • 3Shanxi University, Collaborative Innovation Center of Extreme Optics, Taiyuan, China
  • 4Peking University Yangtze Delta Institute of Optoelectronics, Nantong, China
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    DOI: 10.1117/1.AP.3.6.064002 Cite this Article
    Xiaojiong Chen, Zhaorong Fu, Qihuang Gong, Jianwei Wang. Quantum entanglement on photonic chips: a review[J]. Advanced Photonics, 2021, 3(6): 064002 Copy Citation Text show less


    Entanglement is one of the most vital properties of quantum mechanical systems, and it forms the backbone of quantum information technologies. Taking advantage of nano/microfabrication and particularly complementary metal-oxide-semiconductor manufacturing technologies, photonic integrated circuits (PICs) have emerged as a versatile platform for the generation, manipulation, and measurement of entangled photonic states. We summarize the recent progress of quantum entanglement on PICs, starting from the generation of nonentangled and entangled biphoton states, to the generation of entangled states of multiple photons, multiple dimensions, and multiple degrees of freedom, as well as their applications for quantum information processing.

    1 Introduction

    The famous Einstein–Podolsky–Rosen (EPR) state was originally proposed1 and later named “entangled state”2 for the debate of the completeness of the quantum mechanical description of reality. Pioneering experiments of EPR entanglement have allowed the exclusion of the presence of local hidden variables by violating the Bell inequality3 and allowed significant Bell tests with a closure of detection and distance loopholes.46 Moreover, entanglement has also become the enabling resource for quantum information applications in the fields of quantum communication and networks,7 quantum metrology and imaging,8,9 and quantum computation and simulations.10,11 In all of the above fundamental investigations and technological developments, the photon has been in the core position, owing to its low-noise nature, ease of control, room-temperature operation, and high-speed transmission.12 For example, the loophole-free Bell tests were implemented in entangled photonic systems.46 The photon is recognized as the inevitable carrier for global-scale quantum key distribution13 and quantum internet.14 Recently, Boson sampling with photons was used to demonstrate quantum computational advantages.15 Universal quantum computing with photons is possible with largely entangled cluster states.1618 Integrated quantum photonics provides a compact, reliable, reprogrammable, and scalable platform for the study of fundamental quantum physics and for the implementation of profound quantum applications.19 Leveraging mature complementary metal-oxide-semiconductor (CMOS) fabrication, integrated photonic quantum technology progressed significantly since its first demonstration in the controlled-NOT logic gate on silica waveguide circuits in 2008.20 This includes the development of advanced material systems,2032 implementations of major quantum communication protocols,28,32,33 and proof-of-principle demonstrations of quantum computation and quantum simulation algorithms.3436 We recommend other reviews of those topics in Refs. 19 and 37.

    Copy Citation Text
    Xiaojiong Chen, Zhaorong Fu, Qihuang Gong, Jianwei Wang. Quantum entanglement on photonic chips: a review[J]. Advanced Photonics, 2021, 3(6): 064002
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