Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Chinese Physics B

Quantum optical interferometry via general photon-subtracted two-mode squeezed states*

Li-Li Hou, Jianzhong Xue, Yongxing Sui, Shuai Wang

Published Aug 6, 2019• 7 citations
Publisher

Abstract

We investigate the sensitivity of phase estimation in a Mach–Zehnder interferometer with photon-subtracted two-mode squeezed vacuum states. Our results show that, for given initial squeezing parameter, both symmetric and asymmetric photon subtractions can further improve the quantum Cramér–Rao bound (i.e., the ultimate phase sensitivity), especially for single-mode photon subtraction. On the other hand, the quantum Cramér–Rao bound can be reached by parity detection for symmetric photon-subtracted two-mode squeezed vacuum states at particular values of the phase shift, but it is not valid for asymmetric photon-subtracted two-mode squeezed vacuum states. In addition, compared with the two-mode squeezed vacuum state, the phase sensitivity via parity detection with asymmetric photon-subtracted two-mode squeezed vacuum states will be getting worse. Thus, parity detection may not always be the optimal detection scheme for nonclassical states of light when they are considered as the interferometer states.

DOI
10.1088/1674-1056/ab38a9

Related papers

Application of photon-added two-mode squeezed vacuum states to phase estimation based on Mach-Zehnder interferometer

Shuai Wang, Yongxing Sui, Xiang-Guo Meng

Quantum metrology is to estimate accurately the value of an unknown parameter with the assistance of the quantum effects, in order to break through the standard quantum limit, even reach the Heisenberg limit. In this work, we study the performance of a general photon-added two-mode squeezed vacuum state that is taken as a detection state of a Mach-Zehnder interferometer. Based on quantum Fisher information, within the constraint on the total mean photon number, symmetric and asymmetric photon addition cannot improve the ultimate phase sensitivity. However, for a given initial squeezing parameter, on this occasion, the symmetric and asymmetric photon addition can improve the ultimate phase sensitivity. Compared with the asymmetric photon-added two-mode squeezed vacuum state, the symmetric one can well improve the ultimate phase sensitivity. This may be because it is always better to implement the symmetric photon addition rather than the asymmetric one in order to increase the mean photon number of the resulting state. On the other hand, via parity detection, the symmetric and asymmetric photon-added two-mode squeezed vacuum state can indeed improve the phase sensitivity of a Mach-Zehnder interferometer for a given initial squeezing parameter. Based on the parity detection, within a constraint on the mean photon number, although the two-mode squeezed vacuum state can give the better phase sensitivity at the optimal phase shift (φ = 0), the phase sensitivity offered by the symmetric and asymmetric photon-added two-mode squeezed vacuum states are both more stable around φ = 0 than by the two-mode squeezed vacuum state. In addition, we show that for the symmetric photon-added two-mode squeezed vacuum state, parity detection is an optimal detection only when the optimal phase shift approaches to zero. When the phase shift slightly deviates from zero, the parity detection is not an optimal detection scheme. Finally, for all values of the phase shift, our results also clearly show that the parity detection is not an optimal detection scheme for the asymmetric photon-added two-mode squeezed vacuum state serving as an interferometer state.

Acta Physica Sinica•Jan 1, 2020•0 citations

Quantum optical interferometry via the photon-added two-mode squeezed vacuum states

Yi Ouyang, Shuai Wang, Lijian Zhang

We investigate the sensitivity and resolution of phase estimation in a Mach–Zehnder interferometer with photon-added two-mode squeezed vacuum states (PA-TMSVS) with a photon-number parity measurement scheme. Our results indicate that, when the phase to be estimated is small, the PA-TMSVS offers an improved phase resolution over both the two-mode squeezed vacuum and the photon-subtracted two-mode squeezed vacuum for a given initial squeezing level. In addition, we study the behavior of the quantum Fisher information of the PA-TMSVS, and show that the optimum phase uncertainty predicted by the corresponding Cramer–Rao bound can be achieved with a parity measurement.

Journal of the Optical Society of America B•Jun 3, 2016•70 citations

Gain sensitivity of the Mach-Zehnder interferometer by photon subtraction strategy

Mikhail S. Podoshvedov, Sergey A. Podoshvedov

We study sensitivity of phase estimation of Mach-Zehnder (MZ) interferometer with original two-mode squeezed vacuum (TMSV) state. At the initial stage, the TMSV state is converted into two single-mode squeezed vacuum (SMSV) states, from each of which photons are subtracted by measurement by photon-number resolving (PNR) detector in auxiliary modes. New measurement-induced continuous variable (CV) states of a certain parity can already demonstrate gain sensitivity more than 20 dB in relation to the initial SMSV states at the output from the MZ interferometer and follow to Heisenberg scaling in the case of subtracting a large number of photons in the measuring channels for practical values of the SMSV squeezing 5 dB>. Using only one measurement-induced CV state of a certain parity together with the SMSV state shows an increase in sensitivity of no more than 11 dB. We show that the sensitivity of the phase estimation obtained by measuring the intensity difference of two measurement-induced CV states in two arms of the MZ interferometer can surpass quantum Cramer-Rao (QCR) boundary of the original two SMSV states just in the practical range of input squeezing 5 dB>. In general, the strategy with preliminary subtraction of photons from two SMSV enables greatly enhance the sensitivity of the MZ interferometer in the practical case of small values of squeezing.

arXiv:2405.16261•May 25, 2024•0 citations

Photon subtraction as a way to increase sensitivity of the Mach–Zehnder interferometer

Alina S Fassakhova, Alexander A Koksharov, Dmitry Kuts +1 more

Abstract Choice of the quantum probe state is of key importance to enhance the sensitivity of the Mach–Zehnder (MZ) interferometer beyond the classical one and even approach the quantum Cramér–Rao bound. According to the work of Caves (Caves 1981 Phys. Rev. D 23 1693), the quantum MZ interferometer is a phase-dependent one operating with single-mode squeezed vacuum (SMSV) light coupled with a coherent state. We use the SMSV state with squeezing <10 dB and report a gain in sensitivity of the phase-dependent MZ interferometer of more than 10 dB compared to the original result (Pezze and Smerzi 2008 Phys. Rev. Lett. 100 073601) via photon subtraction. The gain in sensitivity is also observed when measuring the difference in output intensities of the SMSV state with squeezing of < 3 dB from which two, four, and six photons are subtracted and a large coherent state. Overall, subtracting photons from the initially weakly squeezed light can prove to be a more efficient strategy in quantum MZ interferometry compared to highly squeezed SMSV state generation.

Laser Physics Letters•Mar 19, 2025•1 citation

Optical enhanced interferometry with two-mode squeezed twin-Fock states and parity detection*

Li-Li Hou, Shuai Wang, Xuefen Xu

We theoretically investigate the quantum enhanced metrology using two-mode squeezed twin-Fock states and parity detection. Our results indicate that, for a given initial squeezing parameter, compared with the two-mode squeezed vacuum state, both phase sensitivity and resolution can be enhanced when the two-mode squeezed twin-Fock state is considered as an input state of a Mach–Zehnder interferometer. Within a constraint on the total photon number, although the two-mode squeezed vacuum state gives the better phase sensitivity when the phase shift φ to be estimated approaches to zero, the phase sensitivity offered by these non-Gaussian entangled Gaussian states is relatively stable with respect to the phase shift itself. When the phase shift slightly deviates from φ = 0, the phase sensitivity can be still enhanced by the two-mode squeezed twin-Fock state over a broad range of the total mean photon number where the phase uncertainty is still below the quantum standard noise limit. Finally, we numerically prove that the quantum Cramér–Rao bound can be approached with the parity detection.

Chinese Physics B•Jan 7, 2020•11 citations

Quantum metrology with two-mode photon-subtracted squeezed vacuum

Liu Hao, Song Hongbin, Huang Heyu +3 more

We investigate the phase sensitivity of a Mach-Zehnder Interferometer (MZI) with an input of a non-Gaussian quantum entangled state, Two-Mode Photon-Subtracted Squeezed Vacuum states (TMPSSV). Parity detection is carried out at the output of the interferometer to obtain the phase uncertainty, which is a physical parameter that can quantify the sensitivity of interferometry. According to the simulation results, TMPSSV has a smaller phase uncertainty than the Two-Mode Squeezed Vacuum state (TMSV) in the entire range of the squeezing parameter which means the sensitivity of interferometry based on TMPSSV is higher than that of TMSV. Therefore, non-Gaussian entanglement based on TMPSSV provides a promising quantum resource for an ultra-sensitivity optical interferometer far beyond the standard quantum limit.

Tenth International Conference on Information Optics and Photonics•Dec 5, 2024•0 citations
We investigate the sensitivity of phase estimation in a Mach–Zehnder interferometer with photon-subtracted two-mode squeezed vacuum states. Our results show that, for given initial squeezing parameter, both symmetric and asymmetric photon subtractions can further improve the quantum Cramér–Rao bound (i.e., the ultimate phase sensitivity), especially for single-mode photon subtraction. On the other hand, the quantum Cramér–Rao bound can be reached by parity detection for symmetric photon-subtracted two-mode squeezed vacuum states at particular values of the phase shift, but it is not valid for asymmetric photon-subtracted two-mode squeezed vacuum states. In addition, compared with the two-mode squeezed vacuum state, the phase sensitivity via parity detection with asymmetric photon-subtracted two-mode squeezed vacuum states will be getting worse. Thus, parity detection may not always be the optimal detection scheme for nonclassical states of light when they are considered as the interferometer states.
Quantum metrology is to estimate accurately the value of an unknown parameter with the assistance of the quantum effects, in order to break through the standard quantum limit, even reach the Heisenberg limit. In this work, we study the performance of a general photon-added two-mode squeezed vacuum state that is taken as a detection state of a Mach-Zehnder interferometer. Based on quantum Fisher information, within the constraint on the total mean photon number, symmetric and asymmetric photon addition cannot improve the ultimate phase sensitivity. However, for a given initial squeezing parameter, on this occasion, the symmetric and asymmetric photon addition can improve the ultimate phase sensitivity. Compared with the asymmetric photon-added two-mode squeezed vacuum state, the symmetric one can well improve the ultimate phase sensitivity. This may be because it is always better to implement the symmetric photon addition rather than the asymmetric one in order to increase the mean photon number of the resulting state. On the other hand, via parity detection, the symmetric and asymmetric photon-added two-mode squeezed vacuum state can indeed improve the phase sensitivity of a Mach-Zehnder interferometer for a given initial squeezing parameter. Based on the parity detection, within a constraint on the mean photon number, although the two-mode squeezed vacuum state can give the better phase sensitivity at the optimal phase shift (φ = 0), the phase sensitivity offered by the symmetric and asymmetric photon-added two-mode squeezed vacuum states are both more stable around φ = 0 than by the two-mode squeezed vacuum state. In addition, we show that for the symmetric photon-added two-mode squeezed vacuum state, parity detection is an optimal detection only when the optimal phase shift approaches to zero. When the phase shift slightly deviates from zero, the parity detection is not an optimal detection scheme. Finally, for all values of the phase shift, our results also clearly show that the parity detection is not an optimal detection scheme for the asymmetric photon-added two-mode squeezed vacuum state serving as an interferometer state.
We investigate the sensitivity and resolution of phase estimation in a Mach–Zehnder interferometer with photon-added two-mode squeezed vacuum states (PA-TMSVS) with a photon-number parity measurement scheme. Our results indicate that, when the phase to be estimated is small, the PA-TMSVS offers an improved phase resolution over both the two-mode squeezed vacuum and the photon-subtracted two-mode squeezed vacuum for a given initial squeezing level. In addition, we study the behavior of the quantum Fisher information of the PA-TMSVS, and show that the optimum phase uncertainty predicted by the corresponding Cramer–Rao bound can be achieved with a parity measurement.
We study sensitivity of phase estimation of Mach-Zehnder (MZ) interferometer with original two-mode squeezed vacuum (TMSV) state. At the initial stage, the TMSV state is converted into two single-mode squeezed vacuum (SMSV) states, from each of which photons are subtracted by measurement by photon-number resolving (PNR) detector in auxiliary modes. New measurement-induced continuous variable (CV) states of a certain parity can already demonstrate gain sensitivity more than 20 dB in relation to the initial SMSV states at the output from the MZ interferometer and follow to Heisenberg scaling in the case of subtracting a large number of photons in the measuring channels for practical values of the SMSV squeezing 5 dB>. Using only one measurement-induced CV state of a certain parity together with the SMSV state shows an increase in sensitivity of no more than 11 dB. We show that the sensitivity of the phase estimation obtained by measuring the intensity difference of two measurement-induced CV states in two arms of the MZ interferometer can surpass quantum Cramer-Rao (QCR) boundary of the original two SMSV states just in the practical range of input squeezing 5 dB>. In general, the strategy with preliminary subtraction of photons from two SMSV enables greatly enhance the sensitivity of the MZ interferometer in the practical case of small values of squeezing.
Abstract Choice of the quantum probe state is of key importance to enhance the sensitivity of the Mach–Zehnder (MZ) interferometer beyond the classical one and even approach the quantum Cramér–Rao bound. According to the work of Caves (Caves 1981 Phys. Rev. D 23 1693), the quantum MZ interferometer is a phase-dependent one operating with single-mode squeezed vacuum (SMSV) light coupled with a coherent state. We use the SMSV state with squeezing <10 dB and report a gain in sensitivity of the phase-dependent MZ interferometer of more than 10 dB compared to the original result (Pezze and Smerzi 2008 Phys. Rev. Lett. 100 073601) via photon subtraction. The gain in sensitivity is also observed when measuring the difference in output intensities of the SMSV state with squeezing of < 3 dB from which two, four, and six photons are subtracted and a large coherent state. Overall, subtracting photons from the initially weakly squeezed light can prove to be a more efficient strategy in quantum MZ interferometry compared to highly squeezed SMSV state generation.
We theoretically investigate the quantum enhanced metrology using two-mode squeezed twin-Fock states and parity detection. Our results indicate that, for a given initial squeezing parameter, compared with the two-mode squeezed vacuum state, both phase sensitivity and resolution can be enhanced when the two-mode squeezed twin-Fock state is considered as an input state of a Mach–Zehnder interferometer. Within a constraint on the total photon number, although the two-mode squeezed vacuum state gives the better phase sensitivity when the phase shift φ to be estimated approaches to zero, the phase sensitivity offered by these non-Gaussian entangled Gaussian states is relatively stable with respect to the phase shift itself. When the phase shift slightly deviates from φ = 0, the phase sensitivity can be still enhanced by the two-mode squeezed twin-Fock state over a broad range of the total mean photon number where the phase uncertainty is still below the quantum standard noise limit. Finally, we numerically prove that the quantum Cramér–Rao bound can be approached with the parity detection.
We investigate the phase sensitivity of a Mach-Zehnder Interferometer (MZI) with an input of a non-Gaussian quantum entangled state, Two-Mode Photon-Subtracted Squeezed Vacuum states (TMPSSV). Parity detection is carried out at the output of the interferometer to obtain the phase uncertainty, which is a physical parameter that can quantify the sensitivity of interferometry. According to the simulation results, TMPSSV has a smaller phase uncertainty than the Two-Mode Squeezed Vacuum state (TMSV) in the entire range of the squeezing parameter which means the sensitivity of interferometry based on TMPSSV is higher than that of TMSV. Therefore, non-Gaussian entanglement based on TMPSSV provides a promising quantum resource for an ultra-sensitivity optical interferometer far beyond the standard quantum limit.