Adaptive Optical Phase Estimation Using Time-Symmetric Quantum Smoothing

View/ Open
Author(s)
Wheatley, TA
Berry, DW
Yonezawa, H
Nakane, D
Arao, H
Pope, DT
Ralph, TC
Wiseman, HM
Furusawa, A
Huntington, EH
Griffith University Author(s)
Year published
2010
Metadata
Show full item recordAbstract
Quantum parameter estimation has many applications, from gravitational wave detection to quantum key distribution. The most commonly used technique for this type of estimation is quantum filtering, using only past observations. We present the first experimental demonstration of quantum smoothing, a time-symmetric technique that uses past and future observations, for quantum parameter estimation. We consider both adaptive and nonadaptive quantum smoothing, and show that both are better than their filtered counterparts. For the problem of estimating a stochastically varying phase shift on a coherent beam, our theory predicts ...
View more >Quantum parameter estimation has many applications, from gravitational wave detection to quantum key distribution. The most commonly used technique for this type of estimation is quantum filtering, using only past observations. We present the first experimental demonstration of quantum smoothing, a time-symmetric technique that uses past and future observations, for quantum parameter estimation. We consider both adaptive and nonadaptive quantum smoothing, and show that both are better than their filtered counterparts. For the problem of estimating a stochastically varying phase shift on a coherent beam, our theory predicts that adaptive quantum smoothing (the best scheme) gives an estimate with a mean-square error up to 2v2 times smaller than nonadaptive filtering (the standard quantum limit). The experimentally measured improvement is 2.24ᰮ14.
View less >
View more >Quantum parameter estimation has many applications, from gravitational wave detection to quantum key distribution. The most commonly used technique for this type of estimation is quantum filtering, using only past observations. We present the first experimental demonstration of quantum smoothing, a time-symmetric technique that uses past and future observations, for quantum parameter estimation. We consider both adaptive and nonadaptive quantum smoothing, and show that both are better than their filtered counterparts. For the problem of estimating a stochastically varying phase shift on a coherent beam, our theory predicts that adaptive quantum smoothing (the best scheme) gives an estimate with a mean-square error up to 2v2 times smaller than nonadaptive filtering (the standard quantum limit). The experimentally measured improvement is 2.24ᰮ14.
View less >
Journal Title
Physical Review Letters
Volume
104
Issue
9
Copyright Statement
© 2010 American Physical Society. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. Please refer to the journal's website for access to the definitive, published version.
Subject
Mathematical sciences
Physical sciences
Quantum optics and quantum optomechanics
Engineering