Quantum enhanced multiple-phase estimation with multi-mode N00N states

• Published in: Nature communications Vol. 12; no. 1; pp. 5211 - 8
• Main Authors: Hong, Seongjin, ur Rehman, Junaid, Kim, Yong-Su, Cho, Young-Wook, Lee, Seung-Woo, Jung, Hojoong, Moon, Sung, Han, Sang-Wook, Lim, Hyang-Tag
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/400/482; 639/766/483/1255; 639/766/483/481; Cramer-Rao bounds; Humanities and Social Sciences; Metrology; multidisciplinary; Parameter estimation; Parameter sensitivity; Photons; Science; Science (multidisciplinary); Sensitivity enhancement
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-25451-4

Quantum metrology can achieve enhanced sensitivity for estimating unknown parameters beyond the standard quantum limit. Recently, multiple-phase estimation exploiting quantum resources has attracted intensive interest for its applications in quantum imaging and sensor networks. For multiple-phase estimation, the amount of enhanced sensitivity is dependent on quantum probe states, and multi-mode N 00 N states are known to be a key resource for this. However, its experimental demonstration has been missing so far since generating such states is highly challenging. Here, we report generation of multi-mode N 00 N states and experimental demonstration of quantum enhanced multiple-phase estimation using the multi-mode N 00 N states. In particular, we show that the quantum Cramer-Rao bound can be saturated using our two-photon four-mode N 00 N state and measurement scheme using a 4 × 4 multi-mode beam splitter. Our multiple-phase estimation strategy provides a faithful platform to investigate multiple parameter estimation scenarios. N00N states are a key resource in quantum metrology, but the use of their multi-mode extension for multiparameter estimation has been elusive so far. Here, the authors use multi-mode N00N states - with N=2 photons in 4 modes - for multiple-phase estimation saturating the quantum Cramer-Rao bound.