Observation of Quantum Fingerprinting Beating the Classical Limit

Jian-Yu Guan, Feihu Xu, Hua-Lei Yin, Yuan Li, Wei-Jun Zhang, Si-Jing Chen, Xiao-Yan Yang, Li Li, Li-Xing You, Teng-Yun Chen, Zhen Wang, Qiang Zhang, and Jian-Wei Pan

Phys. Rev. Lett. 116, 240502 – Published 13 June 2016

Abstract

Quantum communication has historically been at the forefront of advancements, from fundamental tests of quantum physics to utilizing the quantum-mechanical properties of physical systems for practical applications. In the field of communication complexity, quantum communication allows the advantage of an exponential reduction in the transmitted information over classical communication to accomplish distributed computational tasks. However, to date, demonstrating this advantage in a practical setting continues to be a central challenge. Here, we report a proof-of-principle experimental demonstration of a quantum fingerprinting protocol that for the first time surpasses the ultimate classical limit to transmitted information. Ultralow noise superconducting single-photon detectors and a stable fiber-based Sagnac interferometer are used to implement a quantum fingerprinting system that is capable of transmitting less information than the classical proven lower bound over 20 km standard telecom fiber for input sizes of up to 2 Gbits. The results pave the way for experimentally exploring the advanced features of quantum communication and open a new window of opportunity for research in communication complexity and testing the foundations of physics.

Received 19 March 2016

DOI:https://doi.org/10.1103/PhysRevLett.116.240502

Physics Subject Headings (PhySH)

Optical tests of quantum theory Quantum communication Quantum information with atoms & light Quantum state engineering

Atomic, Molecular & OpticalQuantum Information, Science & Technology

Authors & Affiliations

Jian-Yu Guan^1,2, Feihu Xu³, Hua-Lei Yin^1,2, Yuan Li^1,2, Wei-Jun Zhang⁴, Si-Jing Chen⁴, Xiao-Yan Yang⁴, Li Li^1,2,*, Li-Xing You^4,†, Teng-Yun Chen^1,2, Zhen Wang⁴, Qiang Zhang^1,2,5,‡, and Jian-Wei Pan^1,2,§

¹Department of Modern Physics and National Laboratory for Physical Sciences at Microscale, Shanghai Branch, University of Science and Technology of China, Hefei, Anhui 230026, China
²CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, Shanghai Branch, University of Science and Technology of China, Hefei, Anhui 230026, China
³Research Laboratory of Electronics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
⁴State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
⁵Jinan Institute of Quantum Technology, Jinan, Shandong, 250101, China