Sequential path entanglement for quantum metrology

Xian Min Jin, Cheng Zhi Peng, Youjin Deng, Marco Barbieri, Joshua Nunn, Ian A. Walmsley

Research output: Contribution to journalArticlepeer-review

12 Citations (SciVal)


Path entanglement is a key resource for quantum metrology. Using path-entangled states, the standard quantum limit can be beaten, and the Heisenberg limit can be achieved. However, the preparation and detection of such states scales unfavourably with the number of photons. Here we introduce sequential path entanglement, in which photons are distributed across distinct time bins with arbitrary separation, as a resource for quantum metrology. We demonstrate a scheme for converting polarization Greenberger-Horne-Zeilinger entanglement into sequential path entanglement. We observe the same enhanced phase resolution expected for conventional path entanglement, independent of the delay between consecutive photons. Sequential path entanglement can be prepared comparably easily from polarization entanglement, can be detected without using photon-number-resolving detectors, and enables novel applications.

Original languageEnglish
Article number1779
JournalScientific Reports
Publication statusPublished - 7 May 2013

ASJC Scopus subject areas

  • General


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