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

Interferometry at the Fundamental Quantum Limit Using Squeezed Light

Hudson A. Loughlin, Melissa A. Guidry, J. Ding, Masaya Ono, Benjamin Lou, Malo Le Gall, Xinghui Yin, Eric Glenn Oelker, N. Mavalvala

Published Jan 1, 2025• 0 citations
Publisher

Abstract

We detail the achievement of the fundamental quantum interferometry limit. We present the theory of such a scheme and demonstrate it experimentally with phase- locked squeezed light, double homodyne readout, and the optimal phase estimator.
DOI
10.1364/cleo_fs.2025.pd100_3

Related papers

Continuous-wave Interferometry at the Heisenberg Limit

Hudson A. Loughlin, Melissa A. Guidry, J. Ding +7 more

We present an experiment to reach the fundamental quantum limit of interferometry. We outline the theory and demonstrate it experimentally with phase-locked squeezed light, double homodyne readout, and an optimal phase estimator.

Frontiers in Optics•Jan 1, 2025•0 citations

Distributed quantum metrology with a single squeezed-vacuum source

Dario Gatto, Paolo Facchi A, Frank A. Narducci +1 more

The authors present a technique to overcome the technological limitations of interferometry in quantum metrology by using squeezed light as the quantum resource, on-off detectors, and thus avoiding the need of any auxiliary interferometric channels. Their set-up achieves Heisenberg-limited sensitivity in the estimation of a linear combination of multiple phases

arXiv:1906.12294•Physical Review Research•Nov 25, 2019•45 citations

Approaching the Heisenberg limit with two-mode squeezed states

Ole Steuernagel, Stefan Scheel

Two mode squeezed states can be used to achieve Heisenberg limit scaling in interferometry: a phase shift of $δϕ\approx 2.76 / < N >$ can be resolved. The proposed scheme relies on balanced homodyne detection and can be implemented with current technology. The most important experimental imperfections are studied and their impact quantified.

arXiv:quant-ph/0211182•Journal of Optics B Quantum and Semiclassical Optics•Mar 1, 2004•29 citations

Quantum double lock-in detection via sequential orthogonal quantum mixing

Min Zhuang, Sijie Chen, Jiahao Huang +1 more

High-precision measurement of oscillating signal is a ubiquitous issue in fundamental science and a critical task in practical technologies. In quantum metrology, quantum lock-in detection provide an efficient method for measuring such signal. In general, when the initial phase of the oscillating signal is unknown,quantum double lock-in detection can effectively extract complete information about the signal's amplitude, frequency, and initial phase. Conventional quantum double lock-in detection requires two individual quantum interferometry, each of which must undergo state preparation and readout. However, the time for state preparation and readout need not be negligible in practical experiments. In particular, the time for state preparation is longer than the time for sensing. To save experimental resources, it is challenging to achieve quantum double lock-in detection just via a single quantum interferometry while still extracting complete information about the signal's amplitude, frequency, and initial phase. Here, we present a general protocol for achieving a quantum double lock-in detection just via a single quantum interferometry under a sequential orthogonal periodic multipulse sequences. In particular, if the input state is a Greenberger-Horne-Zeilinger state and two interaction-based operations are applied during interferometry, the measurement precisions for frequency, amplitude, and initial phase can both approach the Heisenberg limit. Our study paves a new way for measuring oscillating signals with a single quantum interferometry, and provides a feasible method for achieving Heisenberg-limited detection of alternating signals.

quant-pharXiv:2609.39498•Oct 1, 2026•0 citations

Quantum-Enhanced Sensing with Squeezed Light: From Fundamentals to Applications

Xing Heng, Lingchen Zhang, Qingyun Yin +4 more

Squeezed light, a prominent non-classical state of light, exhibits reduced quantum noise in one quadrature component below the standard quantum limit (SQL). The property enables quantum-enhanced precision measurements, surpassing the SQL in quantum sensing applications. This review comprehensively introduces the fundamental concepts, classifications, and experimental generation techniques of squeezed light. It further explores its pivotal role and recent advances in diverse quantum sensing domains, including interferometry, gravitational wave detection, magnetometry, force sensing, biomedical sensing, and quantum radar. The review covers theoretical foundations of squeezed states (including quadrature operators and classification schemes, experimental generation techniques in atomic ensembles, nonlinear crystals, and fibers), fundamentals of quantum sensing with squeezed light (from quantum noise theory to quantum-enhanced metrology), and quantum-enhanced sensing applications across the aforementioned domains. Finally, future challenges and opportunities in the field are discussed.

Applied Sciences•Sep 18, 2025•22 citations

Quantum-enhanced optical phase tracking: experiment and ultimate limits

Howard M. Wiseman

We surpass the coherent-state limit to optical phase tracking using a CW phase-squeezed beam. Our phase varies stochastically over a wide range and consequently the best precision is achieved for a finite degree of squeezing.

The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting•Jan 1, 2013•0 citations
Two mode squeezed states can be used to achieve Heisenberg limit scaling in interferometry: a phase shift of δϕ≈2.76/<N>δϕ\approx 2.76 / < N >δϕ≈2.76/<N> can be resolved. The proposed scheme relies on balanced homodyne detection and can be implemented with current technology. The most important experimental imperfections are studied and their impact quantified.
High-precision measurement of oscillating signal is a ubiquitous issue in fundamental science and a critical task in practical technologies. In quantum metrology, quantum lock-in detection provide an efficient method for measuring such signal. In general, when the initial phase of the oscillating signal is unknown,quantum double lock-in detection can effectively extract complete information about the signal's amplitude, frequency, and initial phase. Conventional quantum double lock-in detection requires two individual quantum interferometry, each of which must undergo state preparation and readout. However, the time for state preparation and readout need not be negligible in practical experiments. In particular, the time for state preparation is longer than the time for sensing. To save experimental resources, it is challenging to achieve quantum double lock-in detection just via a single quantum interferometry while still extracting complete information about the signal's amplitude, frequency, and initial phase. Here, we present a general protocol for achieving a quantum double lock-in detection just via a single quantum interferometry under a sequential orthogonal periodic multipulse sequences. In particular, if the input state is a Greenberger-Horne-Zeilinger state and two interaction-based operations are applied during interferometry, the measurement precisions for frequency, amplitude, and initial phase can both approach the Heisenberg limit. Our study paves a new way for measuring oscillating signals with a single quantum interferometry, and provides a feasible method for achieving Heisenberg-limited detection of alternating signals.
Squeezed light, a prominent non-classical state of light, exhibits reduced quantum noise in one quadrature component below the standard quantum limit (SQL). The property enables quantum-enhanced precision measurements, surpassing the SQL in quantum sensing applications. This review comprehensively introduces the fundamental concepts, classifications, and experimental generation techniques of squeezed light. It further explores its pivotal role and recent advances in diverse quantum sensing domains, including interferometry, gravitational wave detection, magnetometry, force sensing, biomedical sensing, and quantum radar. The review covers theoretical foundations of squeezed states (including quadrature operators and classification schemes, experimental generation techniques in atomic ensembles, nonlinear crystals, and fibers), fundamentals of quantum sensing with squeezed light (from quantum noise theory to quantum-enhanced metrology), and quantum-enhanced sensing applications across the aforementioned domains. Finally, future challenges and opportunities in the field are discussed.