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

arXiv:2403.02328 · Physical Review Research

Strong thermomechanical noise squeezing stabilized by feedback

Aida Mashaal, Lucio Stefan, Andrea Ranfagni, Letizia Catalini, Ilia Chernobrovkin, Thibault Capelle, Eric Langman, Albert Schließer

Published Mar 17, 2025• 5 citations
arXivHTMLPDF

Abstract

Squeezing the quadrature noise of a harmonic oscillator enhances its sensitivity. Stabilization of the antisqueezed quadrature can overcome the 3 dB squeezing limit by parametric modulation. Here, we apply this method to soft-clamped membrane resonators, which hold promise for both classical and quantum sensing applications. We compare piezoelectric and capacitive parametric modulation and observe thermomechanical squeezing by up to 17 and 21 dB, respectively. Finally, we provide a full quantum theory of combining this approach with quantum-limited motion measurement. We conclude that quantum squeezing is feasible at moderate cryogenic temperatures and realistic device parameters.

DOI
10.1103/physrevresearch.7.l012071

Related papers

Strong quantum squeezing of mechanical resonator via parametric amplification and coherent feedback

Xiang You, Zongyang Li, Yongmin Li

A scheme to achieve strong quantum squeezing of a mechanical resonator in a membrane-in-the-middle optomechanical system is developed. To this end, simultaneous linear and nonlinear coupling between the mechanical resonator and the cavity modes is applied. A two-tone driving light field, comprising unequal red-detuned and blue-detuned sidebands, helps in generating a coherent feedback force through the linear coupling with the membrane resonator. Another driving light field with its amplitude modulated at twice the mechanical frequency drives the mechanical parametric amplification through a second-order coupling with the resonator. The combined effect produces strong quantum squeezing of the mechanical state. The proposed scheme is quite robust to excess second-order coupling observed in coherent feedback operations and can suppress the fluctuations in the mechanical quadrature to far below the zero point and achieve strong squeezing (greater than 10 dB) for realistic parameters.

Physical Review A•Dec 8, 2017•21 citations

Fast quantum squeezing of a nanomechanical oscillator with an inverted potential

Oscar Schmitt Kremer, Lorenzo Dania, Lukas Novotny +1 more

Nonclassical states of nano- and micro-mechanical motion enable measurements beyond the standard quantum limit and constitute a key resource for quantum sensing and metrology. The most strongly squeezed mechanical states to date have been generated with electromechanical platforms under cryogenic refrigeration and using reservoir engineering. To push mechanical systems deeper into the quantum-squeezed regime requires protocols that increase the rate at which squeezing is generated to more strongly overcome the decoherence rate at which state purity is lost. Here, we squeeze the 800 kHz libration mode of a silica nanoparticle optically levitated in vacuum at room temperature. We expose our mechanical oscillator to an optically generated inverted potential, where the squeezing operation proceeds at an exponentially accelerated rate. We reach a squeezed quadrature variance 11 dB below the vacuum fluctuations within 250 ns. Our protocol establishes a new paradigm for generating quantum squeezing of mechanical motion and offers a platform for quantum-enhanced sensing with massive oscillators.

quant-pharXiv:2609.12833•Sep 14, 2026•0 citations

Quantum dynamics of a cantilever under combined additive and parametric noise: Implications for squeezing and sensitivity control

Wael M. Al-Sawai

We present a comprehensive quantum framework to analyze the dynamics of a nanomechanical cantilever subjected to combined additive and parametric noise. Using the Wigner phase-space representation, we derive and numerically solve c-number stochastic differential equations that accurately capture the evolution of the quantum state under realistic noise conditions. This operator-to-c-number mapping makes the role of quadrature noise sources explicit and provides a transparent route to evaluating squeezing. Our simulations reveal distinct dynamical regimes, demonstrating a critical trade-off determined by the parametric drive strength g0. In the stable regime, parametric modulation suppresses quantum fluctuations, achieving squeezing of about −1.7 dB relative to the vacuum noise limit. For stronger parametric driving, transient squeezing levels approaching −5 dB are observed, but these gains are accompanied by rapid growth of the conjugate quadrature and eventual instability. We further connect these dynamics to effective quality factor enhancement, clarifying the implications for nano-cantilever sensor performance. An explicit check of the Heisenberg uncertainty relation confirms that our simulations remain physically consistent. Together, these results establish a unified framework that links fundamental quantum noise dynamics with practical benchmarks for quantum-enhanced sensing.

Journal of Applied Physics•Oct 22, 2025•3 citations

Noiseless Quantum Measurement and Squeezing of Microwave Fields Utilizing Mechanical Vibrations

Caspar F. Ockeloen-Korppi, Erno Damskägg, J.-M. Pirkkalainen +3 more

A process which strongly amplifies both quadrature amplitudes of an oscillatory signal necessarily adds noise. Alternatively, if the information in one quadrature is lost in phase-sensitive amplification, it is possible to completely reconstruct the other quadrature. Here we demonstrate such a nearly perfect phase-sensitive measurement using a cavity optomechanical scheme, characterized by an extremely small noise less than 0.2 quanta. The device also strongly squeezes microwave radiation by 8 dB below vacuum. A source of bright squeezed microwaves opens up applications in manipulations of quantum systems, and noiseless amplification can be used even at modest cryogenic temperatures.

arXiv:1610.09980•Physical Review Letters•Mar 6, 2017•63 citations

Squeezing of Quantum Noise of Motion in a Micromechanical Resonator

J.-M. Pirkkalainen, Erno Damskägg, M. Brandt +2 more

A pair of conjugate observables, such as the quadrature amplitudes of harmonic motion, have fundamental fluctuations that are bound by the Heisenberg uncertainty relation. However, in a squeezed quantum state, fluctuations of a quantity can be reduced below the standard quantum limit, at the cost of increased fluctuations of the conjugate variable. Here we prepare a nearly macroscopic moving body, realized as a micromechanical resonator, in a squeezed quantum state. We obtain squeezing of one quadrature amplitude 1.1±0.4 dB below the standard quantum limit, thus achieving a long-standing goal of obtaining motional squeezing in a macroscopic object.

arXiv:1507.04209•Physical Review Letters•Dec 7, 2015•400 citations

Multimode optomechanical system in the quantum regime

William Hvidtfelt Padkær Nielsen, Yeghishe Tsaturyan, C. Møller +2 more

) mechanical modes in a phononic-bandgap shielded membrane resonator. An optical mode of a compact Fabry-Perot resonator detects these modes' motion with a measurement rate (96 kHz) that exceeds the mechanical decoherence rates already at moderate cryogenic temperatures (10 K). Reaching this quantum regime entails, inter alia, quantum measurement backaction exceeding thermal forces and thus strong optomechanical quantum correlations. In particular, we observe ponderomotive squeezing of the output light mediated by a multitude of mechanical resonator modes, with quantum noise suppression up to -2.4 dB (-3.6 dB if corrected for detection losses) and bandwidths ≲90 kHz. The multimode nature of the membrane and Fabry-Perot resonators will allow multimode entanglement involving electromagnetic, mechanical, and spin degrees of freedom.

arXiv:1605.06541•Proceedings of the National Academy of Sciences•Dec 20, 2016•4 citations
Squeezing the quadrature noise of a harmonic oscillator enhances its sensitivity. Stabilization of the antisqueezed quadrature can overcome the 3 dB squeezing limit by parametric modulation. Here, we apply this method to soft-clamped membrane resonators, which hold promise for both classical and quantum sensing applications. We compare piezoelectric and capacitive parametric modulation and observe thermomechanical squeezing by up to 17 and 21 dB, respectively. Finally, we provide a full quantum theory of combining this approach with quantum-limited motion measurement. We conclude that quantum squeezing is feasible at moderate cryogenic temperatures and realistic device parameters.
A scheme to achieve strong quantum squeezing of a mechanical resonator in a membrane-in-the-middle optomechanical system is developed. To this end, simultaneous linear and nonlinear coupling between the mechanical resonator and the cavity modes is applied. A two-tone driving light field, comprising unequal red-detuned and blue-detuned sidebands, helps in generating a coherent feedback force through the linear coupling with the membrane resonator. Another driving light field with its amplitude modulated at twice the mechanical frequency drives the mechanical parametric amplification through a second-order coupling with the resonator. The combined effect produces strong quantum squeezing of the mechanical state. The proposed scheme is quite robust to excess second-order coupling observed in coherent feedback operations and can suppress the fluctuations in the mechanical quadrature to far below the zero point and achieve strong squeezing (greater than 10 dB) for realistic parameters.
Nonclassical states of nano- and micro-mechanical motion enable measurements beyond the standard quantum limit and constitute a key resource for quantum sensing and metrology. The most strongly squeezed mechanical states to date have been generated with electromechanical platforms under cryogenic refrigeration and using reservoir engineering. To push mechanical systems deeper into the quantum-squeezed regime requires protocols that increase the rate at which squeezing is generated to more strongly overcome the decoherence rate at which state purity is lost. Here, we squeeze the 800 kHz libration mode of a silica nanoparticle optically levitated in vacuum at room temperature. We expose our mechanical oscillator to an optically generated inverted potential, where the squeezing operation proceeds at an exponentially accelerated rate. We reach a squeezed quadrature variance 11 dB below the vacuum fluctuations within 250 ns. Our protocol establishes a new paradigm for generating quantum squeezing of mechanical motion and offers a platform for quantum-enhanced sensing with massive oscillators.
We present a comprehensive quantum framework to analyze the dynamics of a nanomechanical cantilever subjected to combined additive and parametric noise. Using the Wigner phase-space representation, we derive and numerically solve c-number stochastic differential equations that accurately capture the evolution of the quantum state under realistic noise conditions. This operator-to-c-number mapping makes the role of quadrature noise sources explicit and provides a transparent route to evaluating squeezing. Our simulations reveal distinct dynamical regimes, demonstrating a critical trade-off determined by the parametric drive strength g0. In the stable regime, parametric modulation suppresses quantum fluctuations, achieving squeezing of about −1.7 dB relative to the vacuum noise limit. For stronger parametric driving, transient squeezing levels approaching −5 dB are observed, but these gains are accompanied by rapid growth of the conjugate quadrature and eventual instability. We further connect these dynamics to effective quality factor enhancement, clarifying the implications for nano-cantilever sensor performance. An explicit check of the Heisenberg uncertainty relation confirms that our simulations remain physically consistent. Together, these results establish a unified framework that links fundamental quantum noise dynamics with practical benchmarks for quantum-enhanced sensing.
A process which strongly amplifies both quadrature amplitudes of an oscillatory signal necessarily adds noise. Alternatively, if the information in one quadrature is lost in phase-sensitive amplification, it is possible to completely reconstruct the other quadrature. Here we demonstrate such a nearly perfect phase-sensitive measurement using a cavity optomechanical scheme, characterized by an extremely small noise less than 0.2 quanta. The device also strongly squeezes microwave radiation by 8 dB below vacuum. A source of bright squeezed microwaves opens up applications in manipulations of quantum systems, and noiseless amplification can be used even at modest cryogenic temperatures.
A pair of conjugate observables, such as the quadrature amplitudes of harmonic motion, have fundamental fluctuations that are bound by the Heisenberg uncertainty relation. However, in a squeezed quantum state, fluctuations of a quantity can be reduced below the standard quantum limit, at the cost of increased fluctuations of the conjugate variable. Here we prepare a nearly macroscopic moving body, realized as a micromechanical resonator, in a squeezed quantum state. We obtain squeezing of one quadrature amplitude 1.1±0.4 dB below the standard quantum limit, thus achieving a long-standing goal of obtaining motional squeezing in a macroscopic object.
) mechanical modes in a phononic-bandgap shielded membrane resonator. An optical mode of a compact Fabry-Perot resonator detects these modes' motion with a measurement rate (96 kHz) that exceeds the mechanical decoherence rates already at moderate cryogenic temperatures (10 K). Reaching this quantum regime entails, inter alia, quantum measurement backaction exceeding thermal forces and thus strong optomechanical quantum correlations. In particular, we observe ponderomotive squeezing of the output light mediated by a multitude of mechanical resonator modes, with quantum noise suppression up to -2.4 dB (-3.6 dB if corrected for detection losses) and bandwidths ≲90 kHz. The multimode nature of the membrane and Fabry-Perot resonators will allow multimode entanglement involving electromagnetic, mechanical, and spin degrees of freedom.