pith. sign in

arxiv: 2604.05783 · v2 · pith:7M5GZGAPnew · submitted 2026-04-07 · 🪐 quant-ph · physics.atom-ph· physics.optics

Nonlinear atomic tunnelling boosted by bright squeezed vacuum

Zhejun Jiang , Shengzhe Pan , Jianqi Chen , Mingyu Zhu , Chenhao Zhao , Yiwen Wang , Ru Zhang , Jianshi Lu
show 7 more authors
Lulu Han Suwen Xiong Dian Wu Wenxue Li Shicheng Jiang Hongcheng Ni Jian Wu
This is my paper

Pith reviewed 2026-05-21 09:02 UTC · model grok-4.3

classification 🪐 quant-ph physics.atom-phphysics.optics
keywords bright squeezed vacuumnonlinear tunnelling ionizationangular streakingphotoelectron momentum spectraquantum booststrong-field dynamicscorrelation function
0
0 comments X

The pith

Bright squeezed vacuum light boosts nonlinear atomic tunnelling ionization more than 20-fold over coherent light at equal average energy.

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

The paper establishes that quantum light with special photon correlations can drive nonlinear atomic processes far more efficiently than classical light of the same average intensity. It demonstrates this for tunnelling ionization of isolated atoms, a core process underlying attosecond science. Pulses of bright squeezed vacuum at 300 nJ average energy produce the same ionization effect as coherent pulses carrying 7.1 μJ. The equivalence is read out from the positions of peaks in angular-streaked photoelectron momentum spectra. Control of the boost at fixed average energy is shown by varying the light's correlation function.

Core claim

A BSV light with an average pulse energy of 300 nJ achieves an effective intensity equivalent to that of a coherent light with 7.1 μJ, demonstrating a more than 20-fold quantum boost in nonlinear effect from BSV light, as revealed by matching the peaks of the photoelectron momentum spectra produced by the BSV and coherent light using angular streaking, with further control shown by tuning the correlation function at fixed average pulse energy.

What carries the argument

Angular streaking of photoelectron momentum spectra that maps the positions of momentum peaks to an effective intensity experienced by the atom.

If this is right

  • Nonlinear effects can be enhanced through photon-number fluctuations of quantum light rather than by scaling average intensity.
  • The effective intensity of the driving field can be tuned at constant average pulse energy by changing the correlation function of the BSV.
  • Strong-field processes such as high-harmonic generation may become accessible at lower average powers, reducing sample damage.
  • Quantum statistics provide an independent control knob for tailoring the outcome of multiphoton ionization.

Where Pith is reading between the lines

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

  • If the boost generalizes, attosecond pulse generation could be performed at substantially lower average intensities than currently required.
  • The same statistical enhancement could be tested in other nonlinear phenomena such as above-threshold ionization or laser-induced electron diffraction.
  • Extending the method to molecules would allow quantum-controlled dissociation or isomerization at reduced intensities.

Load-bearing premise

The assumption that peak matching in angular-streaked photoelectron momentum spectra directly and exclusively quantifies an effective intensity boost without residual contributions from non-classical photon statistics or experimental systematics.

What would settle it

A calibration run in which BSV and coherent light are adjusted to produce identical total ionization yields yet yield mismatched momentum peak positions in the angular streaking data would falsify the claim of a pure quantum intensity boost.

read the original abstract

Nonlinear optical processes, mediated by multiphoton interactions rather than single-photon response, are routinely exploited to enable a range of light-based functionalities in devices and applications. Nonlinear effects are enhanced through higher intensity fields, which is a limiting strategy owing to potential radiation damage. An alternative strategy relies on the fluctuation redistribution typical of quantum light, but experimental demonstrations at the most fundamental level have been limited. Here we report experimental nonlinear tunnelling ionization of isolated atoms, a pivotal nonlinear process that drives high-harmonic generation and forms the basis of attosecond science, boosted by quantum light -- bright squeezed vacuum (BSV). A BSV light with an average pulse energy of 300 nJ achieves an effective intensity equivalent to that of a coherent light with 7.1 {\textmu}J, demonstrating a more than 20-fold quantum boost in nonlinear effect from BSV light. This boost is revealed by matching the peaks of the photoelectron momentum spectra produced by the BSV and coherent light using angular streaking. Furthermore, we demonstrate control of the effective intensity of the BSV by tuning the correlation function at fixed average pulse energy, establishing a robust method to tailor nonlinear processes via quantum statistics rather than classical intensity scaling. These findings may facilitate the development of quantum-controlled strong-field dynamics using tailored quantum light sources.

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 reports an experimental demonstration of enhanced nonlinear atomic tunneling ionization using bright squeezed vacuum (BSV) light. A BSV pulse with 300 nJ average energy produces photoelectron momentum spectra peaks (via angular streaking) that match those from coherent light at 7.1 μJ, indicating a >20-fold quantum boost in effective intensity. The work also shows that this effective intensity can be controlled by tuning the second-order correlation function at fixed average pulse energy.

Significance. If the peak-matching procedure isolates a pure intensity boost without residual contributions from BSV photon statistics or pulse-shape differences, the result would constitute a clear experimental advance in quantum-enhanced strong-field physics. It would demonstrate that non-classical light can drive nonlinear processes more efficiently than coherent light at the same average intensity, with potential relevance to attosecond science and high-harmonic generation. The direct spectral comparison and the correlation-tuning control are concrete strengths of the experimental design.

major comments (2)
  1. [Abstract / angular-streaking results] Abstract and results on angular-streaked spectra: the central claim equates the observed momentum peak for 300 nJ BSV to that of 7.1 μJ coherent light. Because tunneling ionization is exponentially sensitive to instantaneous field and BSV is super-Poissonian (g^(2)>1), the ensemble-averaged momentum distribution could shift due to intensity fluctuations independently of any classical intensity rescaling. The manuscript does not provide an explicit model or control that subtracts these contributions from the peak position.
  2. [Abstract] Abstract: the numerical equivalence (300 nJ BSV ≡ 7.1 μJ coherent) is stated without reported uncertainties, without the fitting procedure used to extract the 7.1 μJ value, and without quantitative checks that competing quantum or systematic effects have been ruled out.
minor comments (2)
  1. [Methods] Clarify in the methods how the angular-streaking vector-potential mapping is applied to fluctuating BSV fields versus coherent fields.
  2. [Results] Add error bars or confidence intervals to the reported 7.1 μJ equivalence and to the correlation-function tuning data.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the positive overall assessment of our work and for the constructive comments, which help clarify the interpretation of our angular-streaking results. We address each major comment below and will incorporate revisions to strengthen the presentation of the effective-intensity equivalence.

read point-by-point responses

  1. Referee: [Abstract / angular-streaking results] Abstract and results on angular-streaked spectra: the central claim equates the observed momentum peak for 300 nJ BSV to that of 7.1 μJ coherent light. Because tunneling ionization is exponentially sensitive to instantaneous field and BSV is super-Poissonian (g^(2)>1), the ensemble-averaged momentum distribution could shift due to intensity fluctuations independently of any classical intensity rescaling. The manuscript does not provide an explicit model or control that subtracts these contributions from the peak position.

    Authors: We agree that an explicit separation of fluctuation-driven effects from the claimed quantum boost is essential for the central claim. The peak position in the angular-streaked spectra is set by the highest instantaneous fields that dominate the exponentially sensitive tunneling rate. While BSV intensity fluctuations are present, our control data at fixed average energy but varied g^(2) demonstrate that the peak shift scales with the second-order correlation rather than with classical pulse-shape or average-intensity changes alone. To make this separation quantitative, we will add a supplementary section containing a rate-equation model that convolves the measured BSV photon-number distribution with the tunneling ionization probability and compares the resulting momentum-peak position against both the experimental BSV data and a simulated coherent state possessing identical g^(2). This will explicitly show that the observed 20-fold effective-intensity boost exceeds the shift attributable to super-Poissonian statistics of a classical fluctuating field. revision: yes

  2. Referee: [Abstract] Abstract: the numerical equivalence (300 nJ BSV ≡ 7.1 μJ coherent) is stated without reported uncertainties, without the fitting procedure used to extract the 7.1 μJ value, and without quantitative checks that competing quantum or systematic effects have been ruled out.

    Authors: We accept that the abstract and main-text presentation of the numerical equivalence must be made more rigorous. In the revised manuscript we will (i) report the uncertainty on the 7.1 μJ value obtained from a least-squares fit of the momentum-peak position versus coherent-pulse energy, (ii) describe the fitting procedure and the number of shots used, and (iii) add a quantitative paragraph (with accompanying supplementary figures) that bounds the contributions from pulse-duration mismatch, residual spatial inhomogeneity, and any non-tunneling channels. These checks are already contained in our internal analysis and will be moved into the public record. revision: yes

Circularity Check

0 steps flagged

No significant circularity: direct experimental spectral comparison

full rationale

The paper presents an experimental result based on direct measurement and peak matching of angular-streaked photoelectron momentum spectra between BSV and coherent light sources. The central claim of a >20-fold quantum boost is obtained by comparing observed data at fixed average pulse energies rather than through any mathematical derivation, fitted parameter renamed as prediction, or self-citation chain that reduces the result to its own inputs. No equations or sections invoke self-definitional relations, uniqueness theorems from prior author work, or ansatzes smuggled via citation. The comparison is externally falsifiable via the experimental apparatus and does not rely on renaming known empirical patterns.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Experimental demonstration; no free parameters, axioms, or invented entities are introduced in the abstract. The work relies on standard interpretations of angular streaking and quantum optics that are not re-derived here.

pith-pipeline@v0.9.0 · 5812 in / 1085 out tokens · 45666 ms · 2026-05-21T09:02:36.599813+00:00 · methodology

Review history (2 revisions) →

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

What do these tags mean?
matches
The paper's claim is directly supported by a theorem in the formal canon.
supports
The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
extends
The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
uses
The paper appears to rely on the theorem as machinery.
contradicts
The paper's claim conflicts with a theorem or certificate in the canon.
unclear
Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.

Reference graph

Works this paper leans on

45 extracted references · 45 canonical work pages

  1. [1]

    Becker,et al.,Advances In Atomic, Molecular, and Optical Physics(Academic Press) (2002)

    W. Becker,et al.,Advances In Atomic, Molecular, and Optical Physics(Academic Press) (2002)

    work page 2002

  2. [2]

    Eckle,et al., Attosecond Ionization and Tunneling Delay Time Measurements in Helium

    P. Eckle,et al., Attosecond Ionization and Tunneling Delay Time Measurements in Helium. Science322, 1525–1529 (2008)

    work page 2008

  3. [3]

    J. H. Eberly, J. Javanainen, K. Rza ¸˙ zewski, Above-threshold ionization.Phys. Rep.204, 331–383 (1991)

    work page 1991

  4. [4]

    Meckel,et al., Laser-Induced Electron Tunneling and Diffraction.Science320, 1478–1482 (2008)

    M. Meckel,et al., Laser-Induced Electron Tunneling and Diffraction.Science320, 1478–1482 (2008)

    work page 2008

  5. [5]

    U. S. Sainadh,et al., Attosecond angular streaking and tunnelling time in atomic hydrogen. Nature568, 75–77 (2019)

    work page 2019

  6. [6]

    Akoury,et al., The Simplest Double Slit: Interference and Entanglement in Double Pho- toionization of H2.Science318, 949–952 (2007)

    D. Akoury,et al., The Simplest Double Slit: Interference and Entanglement in Double Pho- toionization of H2.Science318, 949–952 (2007)

    work page 2007

  7. [7]

    M. F. Kling,et al., Control of Electron Localization in Molecular Dissociation.Science312, 246–248 (2006)

    work page 2006

  8. [8]

    S. V. Popruzhenko, Keldysh theory of strong field ionization: history, applications, difficulties and perspectives.J. Phys. B.47(20), 204001 (2014)

    work page 2014

  9. [9]

    Dantus, Ultrafast studies of elusive chemical reactions in the gas phase.Science385, eadk1833 (2024)

    M. Dantus, Ultrafast studies of elusive chemical reactions in the gas phase.Science385, eadk1833 (2024)

    work page 2024

  10. [10]

    Antoine, A

    P. Antoine, A. L ’Huillier, M. Lewenstein, Attosecond Pulse Trains Using High–Order Harmon- ics.Phys. Rev. Lett.77, 1234–1237 (1996)

    work page 1996

  11. [11]

    Schultze,et al., Delay in Photoemission.Science328, 1658–1662 (2010)

    M. Schultze,et al., Delay in Photoemission.Science328, 1658–1662 (2010)

    work page 2010

  12. [12]

    Isinger,et al., Photoionization in the time and frequency domain.Science358, 893–896 (2017)

    M. Isinger,et al., Photoionization in the time and frequency domain.Science358, 893–896 (2017). 12

    work page 2017

  13. [13]

    Kanai, S

    T. Kanai, S. Minemoto, H. Sakai, Quantum interference during high-order harmonic generation from aligned molecules.Nature435, 470–474 (2005)

    work page 2005

  14. [14]

    Niikura,et al., Sub-laser-cycle electron pulses for probing molecular dynamics.Nature417, 917–922 (2002)

    H. Niikura,et al., Sub-laser-cycle electron pulses for probing molecular dynamics.Nature417, 917–922 (2002)

    work page 2002

  15. [15]

    Krausz, M

    F. Krausz, M. Ivanov, Attosecond physics.Rev. Mod. Phys.81, 163–234 (2009)

    work page 2009

  16. [16]

    Sansone,et al., Electron localization following attosecond molecular photoionization.Na- ture465, 763–766 (2010)

    G. Sansone,et al., Electron localization following attosecond molecular photoionization.Na- ture465, 763–766 (2010)

    work page 2010

  17. [17]

    Niikura,et al., Probing molecular dynamics with attosecond resolution using correlated wave packet pairs.Nature421, 826–829 (2003)

    H. Niikura,et al., Probing molecular dynamics with attosecond resolution using correlated wave packet pairs.Nature421, 826–829 (2003)

    work page 2003

  18. [18]

    Wu,et al., Understanding the role of phase in chemical bond breaking with coincidence angular streaking.Nat

    J. Wu,et al., Understanding the role of phase in chemical bond breaking with coincidence angular streaking.Nat. Commun.4, 2177 (2013)

    work page 2013

  19. [19]

    Satya Sainadh, R

    U. Satya Sainadh, R. T. Sang, I. V. Litvinyuk, Attoclock and the quest for tunnelling time in strong-field physics.J. Phys. Photonics2, 042002 (2020)

    work page 2020

  20. [20]

    Yi,et al., Generation of Massively Entangled Bright States of Light during Harmonic Generation in Resonant Media.Phys

    S. Yi,et al., Generation of Massively Entangled Bright States of Light during Harmonic Generation in Resonant Media.Phys. Rev. X15, 011023 (2025)

    work page 2025

  21. [21]

    Stammer,et al., Entanglement and Squeezing of the Optical Field Modes in High Harmonic Generation.Phys

    P. Stammer,et al., Entanglement and Squeezing of the Optical Field Modes in High Harmonic Generation.Phys. Rev. Lett.132, 143603 (2024)

    work page 2024

  22. [22]

    Lewenstein,et al., Generation of optical Schr ¨odinger cat states in intense laser–matter interactions.Nat

    M. Lewenstein,et al., Generation of optical Schr ¨odinger cat states in intense laser–matter interactions.Nat. Phys.17, 1104–1108 (2021)

    work page 2021

  23. [23]

    T. Sh. Iskhakov, A. M. P ´erez, K. Yu. Spasibko, M. V. Chekhova, G. Leuchs, Superbunched bright squeezed vacuum state.Opt. Lett.37, 1919–1921 (2012)

    work page 1919

  24. [24]

    A. M. P ´erez,et al., Bright squeezed-vacuum source with 1.1 spatial mode.Opt. Lett.39, 2403–2406 (2014)

    work page 2014

  25. [25]

    A. M. P´erez,et al., Giant narrowband twin-beam generation along the pump-energy propagation direction.Nat. Commun.6, 7707 (2015). 13

    work page 2015

  26. [26]

    Boitier,et al., Photon extrabunching in ultrabright twin beams measured by two-photon counting in a semiconductor.Nat

    F. Boitier,et al., Photon extrabunching in ultrabright twin beams measured by two-photon counting in a semiconductor.Nat. Commun.2, 425 (2011)

    work page 2011

  27. [27]

    K. Y. Spasibko,et al., Multiphoton Effects Enhanced due to Ultrafast Photon-Number Fluctu- ations.Phys. Rev. Lett.119, 223603 (2017)

    work page 2017

  28. [28]

    Manceau, K

    M. Manceau, K. Y. Spasibko, G. Leuchs, R. Filip, M. V. Chekhova, Indefinite-Mean Pareto Photon Distribution from Amplified Quantum Noise.Phys. Rev. Lett.123, 123606 (2019)

    work page 2019

  29. [29]

    Rasputnyi,et al., High-harmonic generation by a bright squeezed vacuum.Nat

    A. Rasputnyi,et al., High-harmonic generation by a bright squeezed vacuum.Nat. Phys.20, 1960–1965 (2024)

    work page 1960

  30. [30]

    Heimerl,et al., Multiphoton electron emission with non-classical light.Nat

    J. Heimerl,et al., Multiphoton electron emission with non-classical light.Nat. Phys.20, 945– 950 (2024)

    work page 2024

  31. [31]

    M. E. Tzur,et al., Generation of squeezed high-order harmonics.Phys. Rev. Res.6, 033079 (2024)

    work page 2024

  32. [32]

    Gorlach,et al., High-harmonic generation driven by quantum light.Nat

    A. Gorlach,et al., High-harmonic generation driven by quantum light.Nat. Phys.19, 1689– 1696 (2023)

    work page 2023

  33. [33]

    H. Liu, H. Zhang, X. Wang, J. Yuan, Atomic Double Ionization with Quantum Light.Phys. Rev. Lett.134, 123202 (2025)

    work page 2025

  34. [34]

    Rivera-Dean, P

    J. Rivera-Dean, P. Stammer, M. F. Ciappina, M. Lewenstein, Structured Squeezed Light Allows for High-Harmonic Generation in Classical Forbidden Geometries.Phys. Rev. Lett.135, 013801 (2025)

    work page 2025

  35. [35]

    C. S. Lange, T. Hansen, L. B. Madsen, Excitonic Enhancement of Squeezed Light in Quantum- Optical High-Harmonic Generation from a Mott Insulator.Phys. Rev. Lett.135, 043603 (2025)

    work page 2025

  36. [36]

    Fang, F.-X

    Y. Fang, F.-X. Sun, Q. He, Y. Liu, Strong-Field Ionization of Hydrogen Atoms with Quantum Light.Phys. Rev. Lett.130, 253201 (2023)

    work page 2023

  37. [37]

    D ¨orner,et al., Cold Target Recoil Ion Momentum Spectroscopy: a ‘momentum microscope’ to view atomic collision dynamics.Phys

    R. D ¨orner,et al., Cold Target Recoil Ion Momentum Spectroscopy: a ‘momentum microscope’ to view atomic collision dynamics.Phys. Rep.330, 95–192 (2000). 14

    work page 2000

  38. [38]

    Ullrich,et al., Recoil-ion and electron momentum spectroscopy: reaction-microscopes.Rep

    J. Ullrich,et al., Recoil-ion and electron momentum spectroscopy: reaction-microscopes.Rep. Prog. Phys.66, 1463 (2003)

    work page 2003

  39. [39]

    M. V. Ammosov, N. B. Delone, V. P. Krainov, Tunnel ionization of complex atoms and of atomic ions in an alternating electromagnetic field.Sov. Phys. JETP64, 1191 (1986)

    work page 1986

  40. [40]

    X. M. Tong, Z. X. Zhao, C. D. Lin, Theory of molecular tunneling ionization.Phys. Rev. A66, 033402 (2002)

    work page 2002

  41. [41]

    M. Y. Ivanov, M. Spanner, O. Smirnova, Anatomy of strong field ionization.J. Mod. Opt. 52(2-3), 165–184 (2005)

    work page 2005

  42. [42]

    Allevi, M

    A. Allevi, M. Bondani, Direct detection of super-thermal photon-number statistics in second- harmonic generation.Opt. Lett.40, 3089–3092 (2015)

    work page 2015

  43. [43]

    Paleari, A

    F. Paleari, A. Andreoni, G. Zambra, M. Bondani, Thermal photon statistics in spontaneous parametric downconversion.Opt. Express12, 2816–2824 (2004)

    work page 2004

  44. [44]

    Janszky, Y

    J. Janszky, Y. Yushin, Many-photon processes with the participation of squeezed light.Phys. Rev. A36, 1288–1292 (1987)

    work page 1987

  45. [45]

    Even Tzur,et al., Photon-statistics force in ultrafast electron dynamics.Nat

    M. Even Tzur,et al., Photon-statistics force in ultrafast electron dynamics.Nat. Photon.17, 501–509 (2023). Acknowledgments We would like to thank Prof. Jian-Wei Pan for fruitful discussions. Funding:This work was supported by the Quantum Science and Technology—National Science and Technology Major Project (Grant No. 2024ZD0300700), the National Natural S...

    work page 2023