Accessible precisions for estimating two conjugate parameters using
Gaussian probes
- URL: http://arxiv.org/abs/2003.07095v2
- Date: Thu, 19 Mar 2020 13:15:02 GMT
- Title: Accessible precisions for estimating two conjugate parameters using
Gaussian probes
- Authors: Syed M. Assad, Jiamin Li, Yuhong Liu, Ningbo Zhao, Wen Zhao, Ping Koy
Lam, Z. Y. Ou, Xiaoying Li
- Abstract summary: We analyse the precision limits for simultaneous estimation of a pair of conjugate parameters in a displacement channel.
The analysis reveals the optimal measurement scheme and allows us to quantify the best precision for one parameter.
- Score: 8.280321302866371
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We analyse the precision limits for simultaneous estimation of a pair of
conjugate parameters in a displacement channel using Gaussian probes. Having a
set of squeezed states as an initial resource, we compute the Holevo
Cram\'er-Rao bound to investigate the best achievable estimation precisions if
only passive linear operations are allowed to be performed on the resource
prior to probing the channel. The analysis reveals the optimal measurement
scheme and allows us to quantify the best precision for one parameter when the
precision of the second conjugate parameter is fixed. To estimate the conjugate
parameter pair with equal precision, our analysis shows that the optimal probe
is obtained by combining two squeezed states with orthogonal squeezing
quadratures on a 50:50 beam splitter. If different importance are attached to
each parameter, then the optimal mixing ratio is no longer 50:50. Instead it
follows a simple function of the available squeezing and the relative
importance between the two parameters.
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