2020/11/30 by Li-Zheng Liu, Yu-Zhe Zhang, Zheng-Da Li +8 · 163 citations
Computer Science · Physics and Astronomy · #Coherence (philosophical gambling strategy) #Heisenberg limit #Mechanical and Optical Resonators #Phase (matter) #Photon #Photon entanglement #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum entanglement #Quantum limit #Quantum metrology #Quantum sensor #quant-ph
paper · pdf · doi:10.1038/s41566-020-00718-2
published in Nature Photonics 15(2), 137-142 (Nature Portfolio) · 22 pages, 5 figures plus Supplemental Materials
openalex publication_date 2020/11/30 · openalex created_date 2020/12/07 · arxiv created 2021/02/23 · arxiv updated 2021/03/03 · openalex updated_date 2026/08/05
Distributed quantum metrology can enhance the sensitivity for sensing spatially distributed parameters beyond the classical limits. Here we demonstrate distributed quantum phase estimation with discrete variables to achieve Heisenberg limit phase measurements. Based on parallel entanglement in modes and particles, we demonstrate distributed quantum sensing for both individual phase shifts and an averaged phase shift, with an error reduction up to 1.4 dB and 2.7 dB below the shot-noise limit. Furthermore, we demonstrate a combined strategy with parallel mode entanglement and multiple passes of the phase shifter in each mode. In particular, our experiment uses six entangled photons with each photon passing the phase shifter up to six times, and achieves a total number of photon passes N=21 at an error reduction up to 4.7 dB below the shot-noise limit. Our research provides a faithful verification of the benefit of entanglement and coherence for distributed quantum sensing in general quantum networks.