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arxiv: 2605.06263 · v1 · submitted 2026-05-07 · 🪐 quant-ph

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Beating noise in frequency estimation with squeezing and memory in continuous-variable systems

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Pith reviewed 2026-05-08 11:15 UTC · model grok-4.3

classification 🪐 quant-ph
keywords quantum metrologyfrequency estimationsqueezingnon-Markovian dynamicscontinuous-variable systemsquantum Fisher informationquantum Brownian motioninformation backflow
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The pith

Embedding squeezing in the Hamiltonian and exploiting environmental memory can overcome noise in quantum frequency estimation for continuous-variable systems.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper seeks to show that adding squeezing directly to the system Hamiltonian and drawing on the memory effects of non-Markovian environments can protect and even improve the precision of frequency estimation when noise is present. If correct, this would mean quantum metrology advantages survive in realistic open systems instead of requiring perfect isolation. Calculations reveal that squeezing produces a higher-order time dependence in the quantum Fisher information during short evolution times, while finite memory in the quantum Brownian motion model creates information backflow that can exceed the unitary limit. The work also maps out when standard Gaussian measurements reach these improved bounds and when stronger squeezing pushes the optimum beyond them.

Core claim

Embedding squeezing into the system Hamiltonian yields a tunable higher-order time dependence in the quantum Fisher information, which enhances short-time sensitivity for frequency estimation. In the quantum Brownian motion model, finite environmental memory produces information backflow that temporarily restores and can surpass the precision of unitary evolution. Gaussian measurements such as homodyne, heterodyne, and optimized general-dyne operations saturate the quantum Fisher information in identifiable regimes, though larger squeezing increases the chance that non-Gaussian strategies become necessary.

What carries the argument

Squeezing embedded in the system Hamiltonian that modifies the time scaling of the quantum Fisher information, combined with information backflow from finite memory in the quantum Brownian motion model.

If this is right

  • The quantum Fisher information acquires higher-order time dependence in the short-time regime from Hamiltonian squeezing.
  • Non-Markovian memory can produce temporary precision gains that exceed the unitary limit via information backflow.
  • Homodyne, heterodyne, and optimized general-dyne measurements saturate the quantum Fisher information in specific parameter regimes.
  • Stronger squeezing widens the gap between Gaussian measurements and the ultimate bound, indicating when non-Gaussian readouts are required.
  • Joint control of the Hamiltonian and environmental memory provides a concrete path to sustain quantum-enhanced frequency estimation in open systems.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same Hamiltonian-plus-memory strategy might extend to estimating other parameters such as phase or displacement in continuous-variable systems.
  • Platforms with tunable bath correlation times, for example optical or mechanical resonators, offer direct tests of the predicted backflow gains.
  • Environment engineering could prove as important as system control when building practical quantum sensors that operate outside ideal conditions.

Load-bearing premise

The quantum Brownian motion model with finite memory time faithfully represents real environments, and squeezing can be added to the Hamiltonian without introducing uncontrolled extra decoherence.

What would settle it

An experiment that measures the quantum Fisher information or achieved estimation variance for a squeezed continuous-variable oscillator in a bath with controllable correlation time, checking whether short-time scaling improves or precision exceeds the unitary and Markovian cases at chosen evolution intervals.

read the original abstract

Quantum metrology promises precision beyond classical limits, yet environmental noise typically degrades the quantum resources required for such enhancement. In this work, we investigate frequency estimation in noisy continuous-variable systems, focusing on two complementary strategies to mitigate decoherence: Hamiltonian engineering and the exploitation of non-Markovian dynamics. By embedding squeezing directly into the system Hamiltonian, we show that the quantum Fisher information (QFI) may acquire a tunable higher-order time dependence, leading to enhanced sensitivity in the short-time regime. Moving beyond the Markovian approximation, we employ the quantum Brownian motion model to demonstrate that structured environments with finite memory can induce information backflow, temporarily restoring and even improving estimation precision relative to the unitary limit. We further assess the achievability of these bounds via Gaussian measurements, identifying regimes where homodyne, heterodyne, and optimized general-dyne measurements saturate the QFI, and noting that stronger squeezing widens the gap, potentially requiring non-Gaussian measurement strategies. Our results establish that jointly tailoring system Hamiltonian and environmental memory offers a viable route toward robust quantum-enhanced frequency estimation in open systems.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 2 minor

Summary. The manuscript investigates frequency estimation in noisy continuous-variable systems. It proposes embedding squeezing directly into the system Hamiltonian to induce tunable higher-order time dependence in the quantum Fisher information (QFI) for short-time enhancement, and employs the quantum Brownian motion (QBM) model with finite memory to show that non-Markovian dynamics induce information backflow that can temporarily restore or exceed unitary-limit precision. It further evaluates saturation of the QFI by Gaussian measurements (homodyne, heterodyne, and general-dyne) and concludes that jointly engineering the Hamiltonian and exploiting environmental memory provides a viable route to robust quantum-enhanced estimation in open systems.

Significance. If the central derivations hold, the work identifies a concrete strategy for mitigating decoherence in quantum metrology by combining Hamiltonian squeezing with structured non-Markovian environments, potentially extending the practical reach of quantum-enhanced frequency sensing beyond Markovian limits. The explicit assessment of Gaussian measurement achievability is a useful contribution to the field.

major comments (2)
  1. [§3] §3 (QFI derivation with squeezing): the central claim of a tunable higher-order time dependence in the QFI requires an explicit expression for the modified QFI under the engineered Hamiltonian (including the squeezing term) and a clear derivation showing how the scaling arises; without this, the short-time enhancement cannot be verified independently of the model parameters.
  2. [§4] §4 (QBM and information backflow): the demonstration that finite-memory QBM produces backflow exceeding the unitary QFI scaling is load-bearing for the 'viable route' conclusion, yet the manuscript provides no comparison against alternative non-Markovian baths or a parameter sweep confirming the effect is robust rather than specific to the chosen memory kernel.
minor comments (2)
  1. The regimes in which homodyne/heterodyne measurements saturate the QFI versus requiring non-Gaussian strategies should be stated more quantitatively, with explicit bounds on squeezing strength.
  2. Notation for the memory kernel parameters and squeezing strength should be introduced consistently in the main text rather than only in appendices.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their careful reading, positive assessment of the significance, and constructive comments. We address each major comment below, indicating the revisions incorporated into the manuscript.

read point-by-point responses
  1. Referee: [§3] §3 (QFI derivation with squeezing): the central claim of a tunable higher-order time dependence in the QFI requires an explicit expression for the modified QFI under the engineered Hamiltonian (including the squeezing term) and a clear derivation showing how the scaling arises; without this, the short-time enhancement cannot be verified independently of the model parameters.

    Authors: We agree that the derivation requires greater explicitness for independent verification. In the revised manuscript we have expanded Section 3 to present the full expression for the QFI under the squeezing-augmented Hamiltonian. The derivation begins from the modified system Hamiltonian, evolves the initial Gaussian state via the corresponding symplectic transformation, and substitutes into the standard QFI formula for Gaussian states. This yields an explicit short-time expansion containing tunable higher-order terms (arising from the squeezing-induced contributions to the generator) whose coefficients depend on the squeezing strength, thereby confirming the claimed enhancement. revision: yes

  2. Referee: [§4] §4 (QBM and information backflow): the demonstration that finite-memory QBM produces backflow exceeding the unitary QFI scaling is load-bearing for the 'viable route' conclusion, yet the manuscript provides no comparison against alternative non-Markovian baths or a parameter sweep confirming the effect is robust rather than specific to the chosen memory kernel.

    Authors: The quantum Brownian motion model with the selected memory kernel was chosen because it permits an exact, non-perturbative treatment of information backflow. The manuscript demonstrates that this backflow can temporarily exceed the unitary QFI scaling. To strengthen the robustness claim we have added to the revised Section 4 both a parameter sweep over the memory correlation time and a brief discussion of why the essential backflow mechanism is expected to persist in other structured environments with finite memory; a full comparison across every alternative bath model remains outside the scope of the present work. revision: partial

Circularity Check

0 steps flagged

No circularity: derivations use standard QFI and QBM without reducing to inputs by construction

full rationale

The paper computes QFI for frequency estimation under a squeezed Hamiltonian and the quantum Brownian motion master equation with memory. These steps follow from the standard definitions of QFI (via symmetric logarithmic derivative) and the known QBM correlation functions; no parameter is fitted to a subset of results and then relabeled as a prediction, no self-citation supplies a uniqueness theorem that forces the chosen form, and no ansatz is imported without independent justification. The abstract and claims therefore remain self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 0 invented entities

Ledger is inferred from abstract only; full paper would likely reveal additional parameters and assumptions.

free parameters (2)
  • squeezing strength
    Tunable parameter that controls the higher-order time dependence of the QFI.
  • memory kernel parameters
    Parameters of the quantum Brownian motion model that determine the strength and duration of information backflow.
axioms (2)
  • standard math Quantum Fisher information bounds the ultimate precision of unbiased parameter estimation
    Standard result in quantum metrology invoked to quantify sensitivity.
  • domain assumption The quantum Brownian motion model with finite correlation time captures non-Markovian dynamics
    Used to demonstrate information backflow effects.

pith-pipeline@v0.9.0 · 5496 in / 1360 out tokens · 52231 ms · 2026-05-08T11:15:19.227078+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

99 extracted references · 5 canonical work pages

  1. [1]

    × 104 t ℱ (a) |β|=0.5, γ=0.05, n=0 |β|=0, γ=0.05, n=0 |β|=0.5, γ=0.05, n=0.1 |β|=0, γ=0.05, n=0.1 0 20 40 60 80 100 0

  2. [2]

    In the left panel (a),γ=0; the black (continuous) and gray (continuous) curves correspond to |β|=0 and|β|=0.5, respectively

    × 102 1.2 × 103 t ℱ (b) FIG.1:QFI as a function of time. In the left panel (a),γ=0; the black (continuous) and gray (continuous) curves correspond to |β|=0 and|β|=0.5, respectively. In the right panel (b),γ=0.05. Other parameters are fixed atω=2.1,β=−0.5i, andα=i. whereβ=|β|e iδ denotes the squeezing parameter of the system. Note importantly that the incl...

  3. [3]

    Technology Vertical - Quantum Com- munication

    × 102 t F FIG.5:Classical Fisher information (CFI) as a function of time. The CFI corresponding to homodyne and heterodyne measurements are shown in gray (dashed) and black (dot-dashed), respectively, while the dyne-optimal CFI is depicted by the red (continuous) curve. The dyne-optimal CFI coincides with the maximum of the homodyne and heterodyne curves....

  4. [4]

    Giovannetti, S

    V . Giovannetti, S. Lloyd, and L. Maccone, Quantum- enhanced measurements: beating the standard quantum limit, Science306,1330(2004)

  5. [5]

    Giovannetti, S

    V . Giovannetti, S. Lloyd, and L. Maccone, Quantum metrology, Physical review letters96,010401(2006)

  6. [6]

    K ¨ose and D

    E. K ¨ose and D. Braun, Superresolution imaging with multiparameter quantum metrology in passive remote sensing, Physical Review A107,032607(2023)

  7. [7]

    Rosenband, D

    T. Rosenband, D. Hume, P . Schmidt, C.-W. Chou, A. Br- usch, L. Lorini, W. Oskay, R. E. Drullinger, T. M. Fortier, J. E. Stalnaker,et al., Frequency ratio of al+ and hg+ single-ion optical clocks; metrology at the17th decimal place, Science319,1808(2008)

  8. [8]

    A gravitational wave observatory operating beyond the quantum shot-noise limit, Nature Physics7,962(2011)

  9. [9]

    Oelker, T

    E. Oelker, T. Isogai, J. Miller, M. Tse, L. Barsotti, N. Maval- vala, and M. Evans, Audio-band frequency-dependent squeezing for gravitational-wave detectors, Physical re- view letters116,041102(2016)

  10. [10]

    Budker and M

    D. Budker and M. Romalis, Optical magnetometry, Na- ture physics3,227(2007)

  11. [11]

    J. F. Barry, J. M. Schloss, E. Bauch, M. J. Turner, C. A. Hart, L. M. Pham, and R. L. Walsworth, Sensitivity optimiza- tion for nv-diamond magnetometry, Reviews of modern physics92,015004(2020)

  12. [12]

    Patel, L

    R. Patel, L. Zhou, A. Frangeskou, G. Stimpson, B. Breeze, A. Nikitin, M. Dale, E. Nichols, W. Thornley, B. Green, et al., Subnanotesla magnetometry with a fiber-coupled diamond sensor, Physical Review Applied14,044058 (2020)

  13. [13]

    Kanno, J

    S. Kanno, J. Soda, and J. Tokuda, Indirect detection of gravitons through quantum entanglement, Physical Re- view D104,083516(2021)

  14. [14]

    Stray, A

    B. Stray, A. Lamb, A. Kaushik, J. Vovrosh, A. Rodgers, J. Winch, F. Hayati, D. Boddice, A. Stabrawa, A. Nigge- baum,et al., Quantum sensing for gravity cartography, Nature602,590(2022)

  15. [15]

    Seveso, V

    L. Seveso, V . Peri, and M. G. A. Paris, Quantum limits to mass sensing in a gravitational field, Journal of Physics A: Mathematical and Theoretical50,235301(2017)

  16. [16]

    W. Weng, J. D. Anstie, T. M. Stace, G. Campbell, F. N. Baynes, and A. N. Luiten, Nano-kelvin thermometry and temperature control: beyond the thermal noise limit, Physical review letters112,160801(2014)

  17. [17]

    Brunelli, S

    M. Brunelli, S. Olivares, M. Paternostro, and M. G. A. Paris, Qubit-assisted thermometry of a quantum har- monic oscillator, Physical Review A—Atomic, Molecular, and Optical Physics86,012125(2012)

  18. [18]

    M. G. A. Paris, Achieving the landau bound to precision of quantum thermometry in systems with vanishing gap, Journal of Physics A: Mathematical and Theoretical49, 03LT02(2016)

  19. [19]

    K. M. Backes, D. A. Palken, S. A. Kenany, B. M. Brubaker, S. Cahn, A. Droster, G. C. Hilton, S. Ghosh, H. Jackson, S. K. Lamoreaux,et al., A quantum enhanced search for dark matter axions, Nature590,238(2021)

  20. [20]

    Hochberg, Y

    Y. Hochberg, Y. F. Kahn, R. K. Leane, S. Rajendran, K. Van Tilburg, T.-T. Yu, and K. M. Zurek, New ap- proaches to dark matter detection, Nature Reviews Physics4,637(2022)

  21. [21]

    Nagata, R

    T. Nagata, R. Okamoto, J. L. O’brien, K. Sasaki, and S. Takeuchi, Beating the standard quantum limit with four-entangled photons, Science316,726(2007)

  22. [22]

    Pezz ´e and A

    L. Pezz ´e and A. Smerzi, Entanglement, nonlinear dynam- ics, and the heisenberg limit, Physical review letters102, 100401(2009)

  23. [23]

    Untern ¨ahrer, B

    M. Untern ¨ahrer, B. Bessire, L. Gasparini, M. Perenzoni, and A. Stefanov, Super-resolution quantum imaging at the heisenberg limit, Optica5,1150(2018)

  24. [24]

    Zhang, M

    J.-W. Zhang, M. Zhuang, B. Wang, W.-F. Yuan, J.-C. Li, G.-Y. Ding, W.-Q. Ding, L. Chen, S.-J. Chen, F. Zhou, et al., Entanglement-enhanced quantum lock-in detection achieving heisenberg scaling, Nature Communications (2025)

  25. [25]

    C. M. Caves, Quantum-mechanical noise in an interfer- ometer, Physical Review D23,1693(1981)

  26. [26]

    D. J. Wineland, J. J. Bollinger, W. M. Itano, F. Moore, and D. J. Heinzen, Spin squeezing and reduced quan- tum noise in spectroscopy, Physical Review A46, R6797 (1992)

  27. [27]

    M. G. A. Paris, Quantum estimation for quantum tech- nology, International Journal of Quantum Information7, 125(2009). 15

  28. [28]

    T ´oth and I

    G. T ´oth and I. Apellaniz, Quantum metrology from a quantum information science perspective, Journal of Physics A: Mathematical and Theoretical47,424006 (2014)

  29. [29]

    Schnabel, Squeezed states of light and their appli- cations in laser interferometers, Physics Reports684,1 (2017)

    R. Schnabel, Squeezed states of light and their appli- cations in laser interferometers, Physics Reports684,1 (2017)

  30. [30]

    Breuer and F

    H.-P . Breuer and F. Petruccione,The theory of open quan- tum systems(OUP Oxford,2002)

  31. [31]

    Alipour, M

    S. Alipour, M. Mehboudi, and A. Rezakhani, Quan- tum metrology in open systems: dissipative cram ´er-rao bound, Physical review letters112,120405(2014)

  32. [32]

    Smirne, J

    A. Smirne, J. Kołody ´nski, S. F. Huelga, and R. Demkowicz-Dobrza ´nski, Ultimate precision lim- its for noisy frequency estimation, Physical review letters116,120801(2016)

  33. [33]

    J. F. Haase, A. Smirne, J. Kołody ´nski, R. Demkowicz- Dobrza´nski, and S. F. Huelga, Fundamental limits to fre- quency estimation: a comprehensive microscopic per- spective, New Journal of Physics20,053009(2018)

  34. [34]

    Tamascelli, C

    D. Tamascelli, C. Benedetti, H.-P . Breuer, and M. G. A. Paris, Quantum probing beyond pure dephasing, New Journal of Physics22,083027(2020)

  35. [35]

    Monras and M

    A. Monras and M. G. A. Paris, Optimal quantum estima- tion of loss in bosonic channels, Physical review letters 98,160401(2007)

  36. [36]

    Krischek, C

    R. Krischek, C. Schwemmer, W. Wieczorek, H. Wein- furter, P . Hyllus, L. Pezz ´e, and A. Smerzi, Useful mul- tiparticle entanglement and sub-shot-noise sensitivity¡? format?¿ in experimental phase estimation, Physical re- view letters107,080504(2011)

  37. [37]

    Demkowicz-Dobrza ´nski and L

    R. Demkowicz-Dobrza ´nski and L. Maccone, Using entan- glement against noise in quantum metrology, Physical review letters113,250801(2014)

  38. [38]

    K. Wang, X. Wang, X. Zhan, Z. Bian, J. Li, B. C. Sanders, and P . Xue, Entanglement-enhanced quantum metrology in a noisy environment, Physical Review A97,042112 (2018)

  39. [39]

    Falaye, A

    B. Falaye, A. Adepoju, A. Aliyu, M. Melchor, M. Liman, O. Oluwadare, M. Gonz ´alez-Ram´ırez, and K. Oyewumi, Investigating quantum metrology in noisy channels, Sci- entific Reports7,16622(2017)

  40. [40]

    Huang, C

    Z. Huang, C. Macchiavello, and L. Maccone, Usefulness of entanglement-assisted quantum metrology, Physical Review A94,012101(2016)

  41. [41]

    Z. H. Saleem, A. Shaji, and S. K. Gray, Optimal time for sensing in open quantum systems, Physical Review A 108,022413(2023)

  42. [42]

    Rivas, S

    ´A. Rivas, S. F. Huelga, and M. B. Plenio, Quantum non- markovianity: characterization, quantification and detec- tion, Reports on Progress in Physics77,094001(2014)

  43. [43]

    Breuer, E.-M

    H.-P . Breuer, E.-M. Laine, J. Piilo, and B. Vacchini, Collo- quium: Non-markovian dynamics in open quantum sys- tems, Reviews of Modern Physics88,021002(2016)

  44. [44]

    Breuer, E.-M

    H.-P . Breuer, E.-M. Laine, and J. Piilo, Measure for the de- gree of non-markovian behavior of quantum processes in open systems, Physical review letters103,210401(2009)

  45. [45]

    De Vega and D

    I. De Vega and D. Alonso, Dynamics of non-markovian open quantum systems, Reviews of Modern Physics89, 015001(2017)

  46. [46]

    H. Li, J. Zou, and B. Shao, Enhanced quantumness via non-markovianity, Physical Review A104,052201(2021)

  47. [47]

    C ¸ akmak, M

    B. C ¸ akmak, M. Pezzutto, M. Paternostro, and ¨O. M ¨ustecaplıo˘glu, Non-markovianity, coherence, and system-environment correlations in a long-range collision model, Physical Review A96,022109(2017)

  48. [48]

    A. W. Chin, S. F. Huelga, and M. B. Plenio, Quantum metrology in non-markovian environments, Physical re- view letters109,233601(2012)

  49. [49]

    Berrada, Non-markovian effect on the precision of pa- rameter estimation, Physical Review A—Atomic, Molec- ular, and Optical Physics88,035806(2013)

    K. Berrada, Non-markovian effect on the precision of pa- rameter estimation, Physical Review A—Atomic, Molec- ular, and Optical Physics88,035806(2013)

  50. [50]

    Macieszczak, Zeno limit in frequency estimation with non-markovian environments, Physical Review A92, 010102(2015)

    K. Macieszczak, Zeno limit in frequency estimation with non-markovian environments, Physical Review A92, 010102(2015)

  51. [51]

    Yang, Memory effects in quantum metrology, Physical review letters123,110501(2019)

    Y. Yang, Memory effects in quantum metrology, Physical review letters123,110501(2019)

  52. [52]

    X. Yang, X. Long, R. Liu, K. Tang, Y. Zhai, X. Nie, T. Xin, J. Li, and D. Lu, Control-enhanced non-markovian quan- tum metrology, Communications Physics7,282(2024)

  53. [53]

    H. Chen, Y. Chen, J. Liu, Z. Miao, and H. Yuan, Quantum metrology enhanced by leveraging informative noise with error correction, Physical Review Letters133, 190801(2024)

  54. [54]

    Mirkin, M

    N. Mirkin, M. Larocca, and D. Wisniacki, Quantum metrology in a non-markovian quantum evolution, Phys- ical Review A102,022618(2020)

  55. [55]

    Berrada, Optimizing precision in quantum metrol- ogy through engineered environments, Scientific Reports (2026)

    K. Berrada, Optimizing precision in quantum metrol- ogy through engineered environments, Scientific Reports (2026)

  56. [56]

    Bai and J.-H

    S.-Y. Bai and J.-H. An, Floquet engineering to overcome no-go theorem of noisy quantum metrology, Physical Re- view Letters131,050801(2023)

  57. [57]

    M. F. O’Keeffe, L. Horesh, J. F. Barry, D. A. Braje, and I. L. Chuang, Hamiltonian engineering with constrained opti- mization for quantum sensing and control, New Journal of Physics21,023015(2019)

  58. [58]

    H. Zhou, L. S. Martin, M. Tyler, O. Makarova, N. Leitao, H. Park, and M. D. Lukin, Robust higher-order hamil- tonian engineering for quantum sensing with strongly interacting systems, Physical Review Letters131,220803 (2023)

  59. [59]

    Y. Zhai, X. Yang, K. Tang, X. Long, X. Nie, T. Xin, D. Lu, and J. Li, Control-enhanced quantum metrology under markovian noise, Physical Review A107,022602(2023)

  60. [60]

    Cram ´er,Mathematical methods of statistics, Vol.9 (Princeton university press,1999)

    H. Cram ´er,Mathematical methods of statistics, Vol.9 (Princeton university press,1999)

  61. [61]

    C. R. Raoet al., Information and the accuracy attainable in the estimation of statistical parameters, Bull. Calcutta Math. Soc37,81(1945)

  62. [62]

    C. W. Helstrom, Minimum mean-squared error of es- timates in quantum statistics, Physics letters A25,101 (1967)

  63. [63]

    C. W. Helstrom, Quantum detection and estimation the- ory, Journal of statistical physics1,231(1969)

  64. [64]

    S. L. Braunstein and C. M. Caves, Statistical distance and the geometry of quantum states, Physical Review Letters 72,3439(1994)

  65. [65]

    J. Liu, J. Chen, X.-X. Jing, and X. Wang, Quantum fisher information and symmetric logarithmic derivative via anti-commutators, Journal of Physics A: Mathematical and Theoretical49,275302(2016)

  66. [66]

    ˇSafr´anek, A

    D. ˇSafr´anek, A. R. Lee, and I. Fuentes, Quantum param- eter estimation using multi-mode gaussian states, New Journal of Physics17,073016(2015)

  67. [67]

    ˇSafr´anek, Estimation of gaussian quantum states, Journal of Physics A: Mathematical and Theoretical52, 16 035304(2019)

    D. ˇSafr´anek, Estimation of gaussian quantum states, Journal of Physics A: Mathematical and Theoretical52, 16 035304(2019)

  68. [68]

    Gaussian states in continuous variable quantum information

    A. Ferraro, S. Olivares, and M. G. A. Paris, Gaussian states in continuous variable quantum information, arXiv preprint quant-ph/0503237(2005)

  69. [69]

    M. G. Genoni, L. Lami, and A. Serafini, Conditional and unconditional gaussian quantum dynamics, Contempo- rary Physics57,331(2016)

  70. [70]

    Serafini,Quantum Continuous Variables(CRC Press, 2017)

    A. Serafini,Quantum Continuous Variables(CRC Press, 2017)

  71. [71]

    Monras, Phase space formalism for quantum estima- tion of gaussian states, arXiv preprint arXiv:1303.3682 (2013)

    A. Monras, Phase space formalism for quantum estima- tion of gaussian states, arXiv preprint arXiv:1303.3682 (2013)

  72. [72]

    J. Guo, S. Liu, B. Jing, Q. He, and M. Gessner, Metrolog- ical sensitivity beyond gaussian limits with cubic phase states (2025), arXiv:2512.03769[quant-ph]

  73. [73]

    M. G. Genoni, C. Invernizzi, and M. G. A. Paris, Enhance- ment of parameter estimation by kerr interaction, Phys. Rev. A80,033842(2009)

  74. [74]

    Olivares, and M

    Manju, S. Olivares, and M. G. A. Paris, Quadratic and cu- bic scrambling in the estimation of two successive phase- shifts, Advanced Quantum Technologies9, e01012(2026)

  75. [75]

    M. A. C. Rossi, F. Albarelli, and M. G. A. Paris, Enhanced estimation of loss in the presence of kerr nonlinearity, Phys. Rev. A93,053805(2016)

  76. [76]

    M. N. Notarnicola, S. Olivares, and M. G. A. Paris, Joint estimation of noise and nonlinearity in kerr systems, APL Quantum1,10.1063/5.0225120(2024)

  77. [77]

    X. Xiao, H. Liang, and X. Wang, Optimal estimation of gravitation with kerr nonlinearity in an optomechanical system, Quantum Information Processing19,410(2020)

  78. [78]

    Chang, W

    S. Chang, W. Ye, H. Zhang, L. Hu, J. Huang, and S. Liu, Improvement of phase sensitivity in an su(1,1) interfer- ometer via a phase shift induced by a kerr medium, Phys. Rev. A105,033704(2022)

  79. [79]

    Adesso, S

    G. Adesso, S. Ragy, and A. R. Lee, Continuous vari- able quantum information: Gaussian states and beyond, Open Systems & Information Dynamics21,1440001 (2014)

  80. [80]

    Vasile, S

    R. Vasile, S. Olivares, M. G. A. Paris, and S. Maniscalco, Continuous-variable-entanglement dynamics in struc- tured reservoirs, Physical Review A—Atomic, Molecular, and Optical Physics80,062324(2009)

Showing first 80 references.