Optimal Gaussian metrology for generic multimode interferometric circuit

Teruo Matsubara, Paolo Facchi, Vittorio Giovannetti, Kazuya Yuasa*


研究成果: Article査読

20 被引用数 (Scopus)


Bounds on the ultimate precision attainable in the estimation of a parameter in Gaussian quantum metrology are obtained when the average number of bosonic probes is fixed. We identify the optimal input probe state among generic (mixed in general) Gaussian states with a fixed average number of probe photons for the estimation of a parameter contained in a generic multimode interferometric optical circuit, namely, a passive linear circuit preserving the total number of photons. The optimal Gaussian input state is essentially a single-mode squeezed vacuum, and the ultimate precision is achieved by a homodyne measurement on the single mode. We also reveal the best strategy for the estimation when we are given L identical target circuits and are allowed to apply passive linear controls in between with an arbitrary number of ancilla modes introduced.

ジャーナルNew Journal of Physics
出版ステータスPublished - 2019 3月 19

ASJC Scopus subject areas

  • 物理学および天文学(全般)


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