2017/07/31 by Kunkun Wang, Xiaoping Wang, Xiang Zhan +4
Computer Science · Engineering · Physics and Astronomy · #Computer science #Electronic engineering #Engineering #Interferometry #Metrology #Open quantum system #Photonics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum decoherence #Quantum entanglement #Quantum mechanics #Quantum metrology #Quantum network #Quantum sensor #Quantum technology #quant-ph
paper · pdf · doi:10.1103/physreva.97.042112
published as Phys. Rev. A 97, 042112 (2018) · 8 pages, 5 figures, plus supplemental material
arxiv created 2018/01/29 · openalex publication_date 2018/04/19 · arxiv updated 2018/04/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Quantum metrology overcomes standard precision limits and plays a central role in science and technology. Practically, it is vulnerable to imperfections such as decoherence. Here we demonstrate quantum metrology for noisy channels such that entanglement with ancillary qubits enhances the quantum Fisher information for phase estimation but not otherwise. Our photonic experiment covers a range of noise for various types of channels, including for two randomly alternating channels such that assisted entanglement fails for each noisy channel individually. We simulate noisy channels by implementing space-multiplexed dual interferometers with quantum photonic inputs. We demonstrate the advantage of entanglement-assisted protocols in a phase estimation experiment run with either a single-probe or multiprobe approach. These results establish that entanglement with ancillae is a valuable approach for delivering quantum-enhanced metrology. Our approach to entanglement-assisted quantum metrology via a simple linear-optical interferometric network with easy-to-prepare photonic inputs provides a path towards practical quantum metrology.