Abstract
The central issue in quantum parameter estimation is to find out the optimal measurement setup that leads to the ultimate lower bound of an estimation error. We address here a question of whether a Gaussian measurement scheme can achieve the ultimate bound for phase estimation in single-mode Gaussian metrology that exploits single-mode Gaussian probe states in a Gaussian environment. We identify three types of optimal Gaussian measurement setups yielding the maximal Fisher information depending on displacement, squeezing, and thermalization of the probe state. We show that the homodyne measurement attains the ultimate bound for both displaced thermal probe states and squeezed vacuum probe states, whereas for the other single-mode Gaussian probe states, the optimized Gaussian measurement cannot be the optimal setup, although they are sometimes nearly optimal. We then demonstrate that the measurement on the basis of the product quadrature operators X̂ P̂ + P̂ X̂ , i.e., a non-Gaussian measurement, is required to be fully optimal.
| Original language | English |
|---|---|
| Article number | 10 |
| Journal | npj Quantum Information |
| Volume | 5 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Dec 2019 |
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ASJC Scopus subject areas
- Computer Science (miscellaneous)
- Statistical and Nonlinear Physics
- Computer Networks and Communications
- Computational Theory and Mathematics
Cite this
Optimal Gaussian measurements for phase estimation in single-mode Gaussian metrology. / Oh, Changhun; Lee, Changhyoup; Rockstuhl, Carsten; Jeong, Hyunseok; Kim, Jaewan; Nha, Hyunchul; Lee, Su Yong.
In: npj Quantum Information, Vol. 5, No. 1, 10, 01.12.2019.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Optimal Gaussian measurements for phase estimation in single-mode Gaussian metrology
AU - Oh, Changhun
AU - Lee, Changhyoup
AU - Rockstuhl, Carsten
AU - Jeong, Hyunseok
AU - Kim, Jaewan
AU - Nha, Hyunchul
AU - Lee, Su Yong
PY - 2019/12/1
Y1 - 2019/12/1
N2 - The central issue in quantum parameter estimation is to find out the optimal measurement setup that leads to the ultimate lower bound of an estimation error. We address here a question of whether a Gaussian measurement scheme can achieve the ultimate bound for phase estimation in single-mode Gaussian metrology that exploits single-mode Gaussian probe states in a Gaussian environment. We identify three types of optimal Gaussian measurement setups yielding the maximal Fisher information depending on displacement, squeezing, and thermalization of the probe state. We show that the homodyne measurement attains the ultimate bound for both displaced thermal probe states and squeezed vacuum probe states, whereas for the other single-mode Gaussian probe states, the optimized Gaussian measurement cannot be the optimal setup, although they are sometimes nearly optimal. We then demonstrate that the measurement on the basis of the product quadrature operators X̂ P̂ + P̂ X̂ , i.e., a non-Gaussian measurement, is required to be fully optimal.
AB - The central issue in quantum parameter estimation is to find out the optimal measurement setup that leads to the ultimate lower bound of an estimation error. We address here a question of whether a Gaussian measurement scheme can achieve the ultimate bound for phase estimation in single-mode Gaussian metrology that exploits single-mode Gaussian probe states in a Gaussian environment. We identify three types of optimal Gaussian measurement setups yielding the maximal Fisher information depending on displacement, squeezing, and thermalization of the probe state. We show that the homodyne measurement attains the ultimate bound for both displaced thermal probe states and squeezed vacuum probe states, whereas for the other single-mode Gaussian probe states, the optimized Gaussian measurement cannot be the optimal setup, although they are sometimes nearly optimal. We then demonstrate that the measurement on the basis of the product quadrature operators X̂ P̂ + P̂ X̂ , i.e., a non-Gaussian measurement, is required to be fully optimal.
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U2 - 10.1038/s41534-019-0124-4
DO - 10.1038/s41534-019-0124-4
M3 - Article
VL - 5
JO - npj Quantum Information
JF - npj Quantum Information
SN - 2056-6387
IS - 1
M1 - 10
ER -