pith. sign in

arxiv: 2606.21068 · v1 · pith:YAB4DJE4new · submitted 2026-06-19 · 🪐 quant-ph · physics.atom-ph

Finite-Time Electrometry with a Quantum-Regime Single-Ion Phonon Laser

Pith reviewed 2026-06-26 14:38 UTC · model grok-4.3

classification 🪐 quant-ph physics.atom-ph
keywords phonon lasertrapped ionelectrometryquantum sensingopen quantum systemLiouvillian dynamicssymmetry breakingphase space
0
0 comments X

The pith

A quantum-regime phonon laser in a trapped ion senses electric fields with sensitivity set by finite-time relaxation dynamics.

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

The paper reports the first realization of a single-ion phonon laser in the quantum regime with average phonon number below 10, using a trapped calcium-40 ion. It demonstrates electrometry by detecting how weak resonant electric fields break the symmetry of the oscillator's phase-space limit cycle. The authors show that the resulting sensitivity is controlled by the slow relaxation of the open quantum system within the finite experimental time window rather than by steady-state properties. This produces a shot-noise-limited peak sensitivity of 14.15 plus or minus 0.77 microvolts per meter per square root hertz and a minimum detectable field change of roughly 1.83 microvolts per meter. A reader would care because the work shows how non-equilibrium dynamics can be harnessed for practical sensing without requiring perfect isolation from the environment.

Core claim

The authors realize a quantum-regime single-ion phonon laser and demonstrate that its electrometry performance is governed by the finite-time relaxation dynamics of the underlying open quantum system. Slow Liouvillian relaxation, tuned via phonon-laser parameters and correlated with the experimental interaction window, increases dynamic susceptibility while preserving the structural robustness of the limit cycle. When applied to resonant electric fields, this yields a shot-noise-limited sensitivity of 14.15 ± 0.77 μV/m/√Hz and a minimum detectable variation δE_min ≈ 1.83 μV/m.

What carries the argument

Finite-time Liouvillian relaxation dynamics of the open quantum system, which sets the dynamic susceptibility of the phase-space limit cycle to symmetry-breaking electric-field perturbations.

If this is right

  • Tuning the phonon-laser parameters controls sensing performance through the relaxation rate.
  • The quantum regime with average phonon number below 10 enables the reported sensitivity values.
  • The limit cycle remains structurally robust even when relaxation is slowed within the experimental window.
  • The approach provides a practical electrometry platform that does not require sideband cooling as a prerequisite.

Where Pith is reading between the lines

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

  • Similar relaxation engineering could improve sensitivity in other driven oscillators used for force or field detection.
  • Extending the interaction window while keeping technical noise low would further reduce the minimum detectable field if the scaling holds.
  • Direct comparison of the same device operated in the classical versus quantum regime would isolate the contribution of reduced phonon number.

Load-bearing premise

The observed phase-space response arises solely from resonant electric-field-induced symmetry breaking and is not appreciably contaminated by trap imperfections, laser noise, or other technical effects.

What would settle it

Measure the electric-field response while independently varying the Liouvillian relaxation rate through laser-parameter changes and check whether the observed sensitivity scales exactly with the inverse square root of the relaxation time as predicted.

Figures

Figures reproduced from arXiv: 2606.21068 by Jian-Qi Zhang, Jia-Wei Wang, Ji Li, Liang Chen, Mang Feng, Pei-Dong Li, Yuan-Zhang Dong, Zhi-Jiao Deng, Zhuo-Zhu Wu.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 4
Figure 4. Figure 4: (a), the experimentally extracted values [25] at the fixed interaction time tpl show excellent quantitative agreement with open-system simulations. This dynamic behavior reflects the fundamental role of the Liouvillian gap ∆L in dictating the open-system relaxation. Within the experimentally accessible regime, a reduced gap leads to slower relaxation (τ ∼ 1/∆L), which grants the limit cycle a ”softer” phas… view at source ↗
Figure 3
Figure 3. Figure 3: (d) maps the simulated finite-time sensitivity ηE across the non-equilibrium phase diagram after the evolution time tpl. To elucidate the underlying mecha￾nism governing this sensitivity landscape, we analyze the dynamic phase-space response of the phonon laser. We numerically simulate the time-dependent evolution of the phase-space response metric Sϕ = |⟨a⟩|/ p ⟨a †a⟩ (b) Sim. Exp. (a) Sim. FIG. 4. Finite… view at source ↗
read the original abstract

The phonon laser realized in a trapped ion, i.e., a self-sustained mechanical oscillator, has demonstrated the unique characteristics in practically detecting externally applied electric signals without the prerequisite of sideband cooling. Entering the quantum regime via sideband cooling is expected to further improve its sensing performance. Here we report the first experimental realization of a quantum-regime single-ion phonon laser ($\bar{n}<10$) using a trapped $^{40}\mathrm{Ca}^+$ ion and demonstrate electrometry based on its phase-space symmetry-breaking response to weak resonant electric fields. By tuning the phonon-laser parameters, we reveal that the sensing performance is fundamentally governed by the finite-time relaxation dynamics of the underlying open quantum system. We find that a slow Liouvillian relaxation, correlated with the finite experimental interaction window, effectively enhances the dynamic susceptibility while maintaining the structural robustness of the limit cycle. This regime, when applied to the detection of electric fields, produces a shot-noise-limited peak sensitivity of $14.15 \pm 0.77~\mu\mathrm{V/m}/\sqrt{\mathrm{Hz}}$ and a minimum detectable field variation of $\delta E_{\mathrm{min}} \approx 1.83~\mu\mathrm{V/m}$. Our results establish quantum phonon lasers as a practical platform for advanced sensing and highlight the central role of Liouvillian dynamics in non-equilibrium electrometry.

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

1 major / 0 minor

Summary. The paper reports the first experimental realization of a quantum-regime single-ion phonon laser in a trapped 40Ca+ ion with mean phonon number below 10. It demonstrates electrometry via the phase-space symmetry-breaking response to weak resonant electric fields, attributing the performance to finite-time Liouvillian relaxation dynamics of the open quantum system. This yields a reported shot-noise-limited peak sensitivity of 14.15 ± 0.77 μV/m/√Hz and a minimum detectable field variation of δE_min ≈ 1.83 μV/m.

Significance. If the central attribution to quantum-regime dynamics holds after noise characterization, the work establishes a practical platform for non-equilibrium electrometry using phonon lasers that does not require sideband cooling. It provides concrete experimental metrics with error bars and highlights the role of open-system relaxation in enhancing susceptibility while preserving limit-cycle robustness, which could inform other driven-dissipative sensing schemes.

major comments (1)
  1. [Experimental methods and results (sensing protocol and data analysis)] The headline sensitivity claim (abstract) that the observed phase-space response and shot-noise-limited performance arise solely from resonant electric-field-induced symmetry breaking via finite-time Liouvillian relaxation is load-bearing for the central result. The manuscript does not report separate null measurements, calibrations, or upper bounds on technical contributions from trap-potential fluctuations, laser-intensity/phase noise, or residual micromotion at the interaction times and phonon numbers used in the sensing data. This directly impacts the weakest assumption identified in the stress test.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading and constructive feedback on our manuscript. We address the single major comment below.

read point-by-point responses
  1. Referee: The headline sensitivity claim (abstract) that the observed phase-space response and shot-noise-limited performance arise solely from resonant electric-field-induced symmetry breaking via finite-time Liouvillian relaxation is load-bearing for the central result. The manuscript does not report separate null measurements, calibrations, or upper bounds on technical contributions from trap-potential fluctuations, laser-intensity/phase noise, or residual micromotion at the interaction times and phonon numbers used in the sensing data. This directly impacts the weakest assumption identified in the stress test.

    Authors: We agree that the manuscript does not present dedicated null measurements or explicit upper bounds on the listed technical noise sources evaluated at the exact interaction times and mean phonon numbers of the sensing dataset. The shot-noise-limited attribution rests on the observed scaling of the phase-space displacement with integration time together with quantitative agreement between the measured response and the finite-time Liouvillian model. In the revised manuscript we will add a dedicated subsection (or supplementary note) that reports auxiliary calibrations of trap-potential stability, laser intensity/phase noise, and residual micromotion performed under comparable conditions, together with derived upper bounds on their contribution to the observed sensitivity. This addition will make the noise-budget analysis explicit and directly address the concern. revision: yes

Circularity Check

0 steps flagged

No circularity: experimental measurements of sensitivity

full rationale

The paper presents an experimental demonstration of a quantum-regime single-ion phonon laser and its use for electrometry. The headline sensitivity values (14.15 ± 0.77 μV/m/√Hz and δE_min ≈ 1.83 μV/m) are obtained from direct measurements of phase-space symmetry breaking under applied resonant fields, with the finite-time Liouvillian dynamics invoked only as the physical mechanism explaining the observed response. No derivation chain reduces a claimed prediction to a fitted parameter by construction, no self-citation is load-bearing for the central result, and no ansatz or uniqueness theorem is smuggled in. The work is self-contained against external benchmarks via reported experimental data.

Axiom & Free-Parameter Ledger

1 free parameters · 1 axioms · 0 invented entities

The central claim rests on the experimental realization of the phonon laser and the interpretation that finite-time Liouvillian relaxation controls the dynamic susceptibility; no new entities are postulated and the only background assumptions are standard open-quantum-system theory.

free parameters (1)
  • phonon-laser drive parameters
    Tuned experimentally to place the system in the slow-relaxation regime within the finite interaction window.
axioms (1)
  • domain assumption The trapped-ion system is accurately described by a Markovian open quantum system whose time evolution is generated by a Liouvillian superoperator.
    Invoked to explain why slow relaxation enhances susceptibility while preserving limit-cycle robustness.

pith-pipeline@v0.9.1-grok · 5802 in / 1315 out tokens · 27883 ms · 2026-06-26T14:38:50.410357+00:00 · methodology

discussion (0)

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

Reference graph

Works this paper leans on

37 extracted references · 31 canonical work pages · 2 internal anchors

  1. [1]

    Wallentowitz , author W

    author author S. Wallentowitz , author W. Vogel , author I. Siemers ,\ and\ author P. E. \ Toschek ,\ title title Vibrational amplification by stimulated emission of radiation ,\ https://doi.org/10.1103/PhysRevA.54.943 journal journal Phys. Rev. A \ volume 54 ,\ pages 943 ( year 1996 ) NoStop

  2. [2]

    Ozdemir , author X.-Y. \ L\

    author author H. Jing , author S. K. \ \"Ozdemir , author X.-Y. \ L\"u , author J. Zhang , author L. Yang ,\ and\ author F. Nori ,\ title title PT -symmetric phonon laser ,\ https://doi.org/10.1103/PhysRevLett.113.053604 journal journal Phys. Rev. Lett. \ volume 113 ,\ pages 053604 ( year 2014 ) NoStop

  3. [3]

    author author K. J. \ Vahala , author Q. Xu , author W. Yang , author O. Painter , author T. Carmon ,\ and\ author T. J. \ Kippenberg ,\ title title A phonon laser ,\ https://doi.org/10.1038/nphys1344 journal journal Nature Physics \ volume 5 ,\ pages 682 ( year 2009 ) NoStop

  4. [4]

    author author I. S. \ Grudinin , author H. Lee , author O. Painter ,\ and\ author K. J. \ Vahala ,\ title title Phonon laser action in a tunable two-level system ,\ https://doi.org/10.1103/PhysRevLett.104.083901 journal journal Phys. Rev. Lett. \ volume 104 ,\ pages 083901 ( year 2010 ) NoStop

  5. [5]

    author author R. M. \ Pettit , author W. Ge , author P. Kumar , author D. R. \ Luntz-Martin , author J. T. \ Schultz , author L. P. \ Neukirch , author M. Bhattacharya ,\ and\ author A. N. \ Vamivakas ,\ title title An optical tweezer phonon laser ,\ https://doi.org/10.1038/s41566-019-0395-5 journal journal Nature Photonics \ volume 13 ,\ pages 402 ( year...

  6. [6]

    Behrle , author T

    author author T. Behrle , author T. L. \ Nguyen , author F. Reiter , author D. Baur , author B. de Neeve , author M. Stadler , author M. Marinelli , author F. Lancellotti , author S. F. \ Yelin ,\ and\ author J. P. \ Home ,\ title title Phonon laser in the quantum regime ,\ https://doi.org/10.1103/PhysRevLett.131.043605 journal journal Phys. Rev. Lett. \ ...

  7. [7]

    \ Dong , author S.-W

    author author Y.-Z. \ Dong , author S.-W. \ He , author Z.-J. \ Deng , author P.-D. \ Li , author L. Chen ,\ and\ author M. Feng ,\ title title Single-ion phonon laser in quantum region ,\ https://doi.org/10.7498/aps.74.20250603 journal journal Acta Physica Sinica \ volume 74 ,\ pages 193701 ( year 2025 ) NoStop

  8. [9]

    author author C. L. \ Degen , author F. Reinhard ,\ and\ author P. Cappellaro ,\ title title Quantum sensing ,\ https://doi.org/10.1103/RevModPhys.89.035002 journal journal Rev. Mod. Phys. \ volume 89 ,\ pages 035002 ( year 2017 ) NoStop

  9. [10]

    author author S. C. \ Burd , author R. Srinivas , author J. J. \ Bollinger , author A. C. \ Wilson , author D. J. \ Wineland , author D. Leibfried , author D. H. \ Slichter ,\ and\ author D. T. C. \ Allcock ,\ title title Quantum amplification of mechanical oscillator motion ,\ https://doi.org/10.1126/science.aaw2884 journal journal Science \ volume 364 ,...

  10. [11]

    author author K. A. \ Gilmore , author M. Affolter , author R. J. \ Lewis-Swan , author D. Barberena , author E. Jordan , author A. M. \ Rey ,\ and\ author J. J. \ Bollinger ,\ title title Quantum-enhanced sensing of displacements and electric fields with two-dimensional trapped-ion crystals ,\ https://doi.org/10.1126/science.abi5226 journal journal Scien...

  11. [12]

    author author P. A. \ Ivanov , author K. Singer , author N. V. \ Vitanov ,\ and\ author D. Porras ,\ title title Quantum sensors assisted by spontaneous symmetry breaking for detecting very small forces ,\ https://doi.org/10.1103/PhysRevApplied.4.054007 journal journal Phys. Rev. Appl. \ volume 4 ,\ pages 054007 ( year 2015 ) NoStop

  12. [13]

    Physical Review A , volume =

    author author S. Fern\'andez-Lorenzo \ and\ author D. Porras ,\ title title Quantum sensing close to a dissipative phase transition: Symmetry breaking and criticality as metrological resources ,\ https://doi.org/10.1103/PhysRevA.96.013817 journal journal Phys. Rev. A \ volume 96 ,\ pages 013817 ( year 2017 ) NoStop

  13. [14]

    author author T. E. \ Lee \ and\ author H. R. \ Sadeghpour ,\ title title Quantum synchronization of quantum van der pol oscillators with trapped ions ,\ https://doi.org/10.1103/PhysRevLett.111.234101 journal journal Phys. Rev. Lett. \ volume 111 ,\ pages 234101 ( year 2013 ) NoStop

  14. [15]

    Walter , author A

    author author S. Walter , author A. Nunnenkamp ,\ and\ author C. Bruder ,\ title title Quantum synchronization of a driven self-sustained oscillator ,\ https://doi.org/10.1103/PhysRevLett.112.094102 journal journal Phys. Rev. Lett. \ volume 112 ,\ pages 094102 ( year 2014 ) NoStop

  15. [16]

    L\"orch , author E

    author author N. L\"orch , author E. Amitai , author A. Nunnenkamp ,\ and\ author C. Bruder ,\ title title Genuine quantum signatures in synchronization of anharmonic self-oscillators ,\ https://doi.org/10.1103/PhysRevLett.117.073601 journal journal Phys. Rev. Lett. \ volume 117 ,\ pages 073601 ( year 2016 ) NoStop

  16. [17]

    Li , author Z

    author author Y. Li , author Z. Xie , author X. Yang , author Y. Li , author X. Zhao , author X. Cheng , author X. Peng , author J. Li , author E. Lutz , author Y. Lin ,\ and\ author J. Du ,\ title title Experimental realization and synchronization of a quantum van der pol oscillator ,\ https://doi.org/10.1126/sciadv.ady5649 journal journal Science Advanc...

  17. [18]

    Liu , author Q

    author author J. Liu , author Q. Wu , author J. E. \ Moore , author H. Haeffner ,\ and\ author C. W. \ Wächtler ,\ https://arxiv.org/abs/2509.18423 title Observation of synchronization between two quantum van der pol oscillators in trapped ions ( year 2025 ),\ https://arxiv.org/abs/2509.18423 arXiv:2509.18423 [quant-ph] NoStop

  18. [19]

    Vicentini , author F

    author author F. Vicentini , author F. Minganti , author R. Rota , author G. Orso ,\ and\ author C. Ciuti ,\ title title Critical slowing down in driven-dissipative bose-hubbard lattices ,\ https://doi.org/10.1103/PhysRevA.97.013853 journal journal Phys. Rev. A \ volume 97 ,\ pages 013853 ( year 2018 ) NoStop

  19. [20]

    Minganti , author A

    author author F. Minganti , author A. Biella , author N. Bartolo ,\ and\ author C. Ciuti ,\ title title Spectral theory of liouvillians for dissipative phase transitions ,\ https://doi.org/10.1103/PhysRevA.98.042118 journal journal Phys. Rev. A \ volume 98 ,\ pages 042118 ( year 2018 ) NoStop

  20. [21]

    Garbe , author M

    author author L. Garbe , author M. Bina , author A. Keller , author M. G. A. \ Paris ,\ and\ author S. Felicetti ,\ title title Critical quantum metrology with a finite-component quantum phase transition ,\ https://doi.org/10.1103/PhysRevLett.124.120504 journal journal Phys. Rev. Lett. \ volume 124 ,\ pages 120504 ( year 2020 ) NoStop

  21. [23]

    \ Li , author G.-Y

    author author P.-D. \ Li , author G.-Y. \ Ding , author J.-Q. \ Zhang , author Q. Yuan , author S.-Q. \ Dai , author T.-H. \ Cui , author F. Zhou , author L. Chen , author Q. Zhong , author H. Jing , author S . K . \"O zdemir ,\ and\ author M. Feng ,\ title title Experimental demonstration of single-spin stirling engine cycles with enhanced efficiency ,\ ...

  22. [24]

    \ Wu , author P.-D

    author author Z.-Z. \ Wu , author P.-D. \ Li , author T.-H. \ Cui , author J.-W. \ Wang , author Y.-Z. \ Dong , author S.-Q. \ Dai , author J. Li , author Y.-Q. \ Wei , author Q. Yuan , author X.-M. \ Cai , author L. Chen , author J.-Q. \ Zhang , author H. Jing ,\ and\ author M. Feng ,\ title title Experimental witness of quantum jump induced high-order l...

  23. [25]

    @noop note See Supplemental Materials for details on the experimental setup and calibrations, theoretical derivations of the semiclassical limits, and numerical simulations of the open-system dynamics. Stop

  24. [27]

    Leibfried , author D

    author author D. Leibfried , author D. M. \ Meekhof , author B. E. \ King , author C. Monroe , author W. M. \ Itano ,\ and\ author D. J. \ Wineland ,\ title title Experimental determination of the motional quantum state of a trapped atom ,\ https://doi.org/10.1103/PhysRevLett.77.4281 journal journal Phys. Rev. Lett. \ volume 77 ,\ pages 4281 ( year 1996 ) NoStop

  25. [28]

    author author W. M. \ Itano , author J. C. \ Bergquist , author J. J. \ Bollinger , author J. M. \ Gilligan , author D. J. \ Heinzen , author F. L. \ Moore , author M. G. \ Raizen ,\ and\ author D. J. \ Wineland ,\ title title Quantum projection noise: Population fluctuations in two-level systems ,\ https://doi.org/10.1103/PhysRevA.47.3554 journal journal...

  26. [29]

    \ Lee , author K.-T

    author author C.-Y. \ Lee , author K.-T. \ Lin ,\ and\ author G.-D. \ Lin ,\ title title Prototype of a phonon laser with trapped ions ,\ https://doi.org/10.1103/PhysRevResearch.5.023082 journal journal Phys. Rev. Res. \ volume 5 ,\ pages 023082 ( year 2023 ) NoStop

  27. [30]

    \ Lee \ and\ author G.-D

    author author C.-Y. \ Lee \ and\ author G.-D. \ Lin ,\ https://arxiv.org/abs/2601.05575 title Bath-free squeezed phonon lasing via intrinsic ion-phonon coupling ( year 2026 ),\ https://arxiv.org/abs/2601.05575 arXiv:2601.05575 [quant-ph] NoStop

  28. [31]

    Quan- tum metrology with nonclassical states of atomic ensembles,

    author author L. Pezz\`e , author A. Smerzi , author M. K. \ Oberthaler , author R. Schmied ,\ and\ author P. Treutlein ,\ title title Quantum metrology with nonclassical states of atomic ensembles ,\ https://doi.org/10.1103/RevModPhys.90.035005 journal journal Rev. Mod. Phys. \ volume 90 ,\ pages 035005 ( year 2018 ) NoStop

  29. [32]

    author author C. D. \ Marciniak , author T. Feldker , author I. Pogorelov , author R. Kaubruegger , author D. V. \ Vasilyev , author R. van Bijnen , author P. Schindler , author P. Zoller , author R. Blatt ,\ and\ author T. Monz ,\ title title Optimal metrology with programmable quantum sensors ,\ https://doi.org/10.1038/s41586-022-04435-4 journal journal...

  30. [33]

    Zhang , author B

    author author J. Zhang , author B. Peng , author S . K. \ \"O zdemir , author K. Pichler , author D. O. \ Krimer , author G. Zhao , author F. Nori , author Y.-x. \ Liu , author S. Rotter ,\ and\ author L. Yang ,\ title title A phonon laser operating at an exceptional point ,\ https://doi.org/10.1038/s41566-018-0213-5 journal journal Nature Photonics \ vol...

  31. [34]

    Jiang , author S

    author author Y. Jiang , author S. Maayani , author T. Carmon , author F. Nori ,\ and\ author H. Jing ,\ title title Nonreciprocal phonon laser ,\ https://doi.org/10.1103/PhysRevApplied.10.064037 journal journal Phys. Rev. Appl. \ volume 10 ,\ pages 064037 ( year 2018 ) NoStop

  32. [35]

    Quantum dynamics of single trapped ions,

    author author D. Leibfried , author R. Blatt , author C. Monroe , \ and\ author D. Wineland ,\ 10.1103/RevModPhys.75.281 journal journal Rev. Mod. Phys. \ volume 75 ,\ pages 281 ( year 2003 ) NoStop

  33. [36]

    author author D. J. \ Wineland , author C. Monroe , author W. M. \ Itano , author D. Leibfried , author B. E. \ King , \ and\ author D. M. \ Meekhof ,\ @noop journal journal Journal of research of the National Institute of Standards and Technology \ volume 103 ,\ pages 259 ( year 1998 ) NoStop

  34. [37]

    Dutta \ and\ author N

    author author S. Dutta \ and\ author N. R. \ Cooper ,\ 10.1103/PhysRevLett.123.250401 journal journal Phys. Rev. Lett. \ volume 123 ,\ pages 250401 ( year 2019 ) NoStop

  35. [38]

    Baur , author T

    author author D. Baur , author T. Behrle , author I. Rojkov , author J. Jeske , author S. Yelin , author J. Home , \ and\ author F. Reiter ,\ https://arxiv.org/abs/2604.18295 title Quantum theory for phonon lasing and non-classical state generation in mixed-species and single trapped ions , \ ( year 2026 ),\ http://arxiv.org/abs/2604.18295 arXiv:2604.1829...

  36. [39]

    Fl¨ uhmann and J

    author author C. Fl\"uhmann \ and\ author J. P. \ Home ,\ 10.1103/PhysRevLett.125.043602 journal journal Phys. Rev. Lett. \ volume 125 ,\ pages 043602 ( year 2020 ) NoStop

  37. [40]

    author author C. C. \ Gerry \ and\ author P. L. \ Knight ,\ @noop title Introductory quantum optics \ ( publisher Cambridge university press ,\ year 2023 ) NoStop