Pith. sign in

REVIEW 4 major objections 4 minor 65 references

Measurement-induced generation of Schr\"{o}dinger cat states in cavity QED

T0 review · 4 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read A cavity field becomes a Schrödinger cat after a single atomic postselection, and repeating the cycle doubles the number of coherent components each time.

desk verdict The two-component cat recipe is a known 1992 scheme; the iterative extension is plausible but contains a concrete error in Eq. (7) and a 2^N scaling claim that fails for the authors' own parameters. read the letter →

arxiv 2608.04578 v1 pith:UDB37UKH submitted 2026-08-05 quant-ph

classification quant-ph MSC 81V8081P40 PACS 42.50.Pq42.50.Dv
keywords SchrödingercatstatescavityQEDpostselectionquantumeraserdispersiveinteractionWignerfunctionnegativitynon-GaussianstategenerationLindbladmasterequation
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper proposes a way to make Schrödinger cat states in a cavity without strong nonlinearities or engineered dissipation: drive the cavity coherently, let a flying two-level atom interact dispersively with the field, then postselect the atom in a superposition basis. Because the dispersive interaction entangles each coherent-state branch with a different atomic state, the atom carries which-way information about the cavity; measuring the atom in a superposition basis erases that information and projects the cavity into a coherent superposition of two phase-separated coherent states, with a negative Wigner function. Repeating the drive–interaction–postselection cycle doubles the number of components each time, so after N cycles the cavity holds a 2^N-component cat state. Lindblad simulations show the negativity survives moderate cavity photon loss, though loss also makes the interference pattern asymmetric. If correct, this gives an experimentally simple, conditional route to non-Gaussian continuous-variable states.

What carries the argument

The load-bearing mechanism is conditional quantum erasure orchestrated by the dispersive atom–cavity Hamiltonian. The interaction of the form $\chi a^\dagger a \sigma_z$ imprints a photon-number-dependent phase onto the atomic superposition, creating which-way information that distinguishes the two coherent-state branches. The postselection projector $|\psi_f\rangle\langle\psi_f|$ then erases this which-way information, restoring coherence between branches. The recursive splitting rule maps each component $|\beta_i\rangle$ to two new components $|(\beta_i-i\eta\tau_1)e^{-i\chi\tau_2}\rangle$ and $|(\beta_i-i\eta\tau_1)e^{i\chi\tau_2}\rangle$ with weights $\cos^2\theta$ and $\sin^2\theta$, which is what doubles the component count every cycle.

What would settle it

After a single cycle with parameters $\chi\tau_2=\pi/2$ and $\eta\tau_1=2$, tomographically reconstruct the Wigner function of the cavity state conditioned on atomic postselection in a superposition basis; a true cat state requires a negative interference fringe between the two coherent peaks, so observing only two positive Gaussian blobs with no negativity would falsify the central claim.

Watch

Extended reading notes

Core claim

The central claim is that a quantum eraser operation, implemented by atomic postselection, converts Gaussian cavity evolution into non-Gaussian state preparation. In the closed-system limit, starting from vacuum, resonant driving displaces the field to $|-i\eta\tau_1\rangle$; a dispersive interaction $H_{\rm int}=\chi a^\dagger a \sigma_z$ for time $\tau_2$ rotates the two atomic components oppositely, producing $\cos\theta|e; -i\eta\tau_1 e^{-i\chi\tau_2}\rangle + \sin\theta|g; -i\eta\tau_1 e^{i\chi\tau_2}\rangle$. Postselecting the atom on $|\psi_f\rangle = \cos\theta|e\rangle + \sin\theta|g\rangle$ yields a superposition of two coherent states with relative weights $\cos^2\theta$ and $\sin^2\theta$. A recursive relation shows each existing component splits into two under an additional cycle, so the number of coherent-state components grows as $2^N$. The Wigner function exhibits interference fringes and negative regions characteristic of a cat state, and numerical solution of the Lindblad equation indicates these features persist under moderate cavity decay.

Load-bearing premise

The protocol assumes the atom's path information is perfectly stored and perfectly erased: no atomic decay, no missed detection, and no residual excitation, so postselection leaves a pure coherent-state superposition.

Editorial extensions

If this is right

  • A single drive–interaction–postselection cycle prepares a two-component Schrödinger cat with Wigner negativity, starting from vacuum.
  • Each additional cycle doubles the number of coherent-state components, giving $2^N$-component cat states whose interference pattern becomes a two-dimensional network.
  • The protocol avoids Kerr nonlinearities, photon subtraction, and engineered dissipation, requiring only coherent driving, a dispersive interaction, and a projective atomic measurement.
  • Moderate cavity photon loss preserves negative Wigner regions, so the scheme is compatible with realistic cavity-QED parameters rather than requiring a fully closed system.
  • The normalization of the postselected state acts as the success probability, so the scheme is inherently probabilistic but repeatable.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Extending the paper's model to include atomic spontaneous emission or finite detection efficiency would likely wash out the Wigner negativity, because imperfect erasure of which-way information leaves a mixed state; this is a direct testable prediction of the erasure picture the paper invokes.
  • Repeating many cycles will make the success probability decay roughly as the product of per-cycle postselection probabilities, so there is an unavoidable trade-off between component number and preparation rate that the paper does not quantify.
  • The same conditional-erasure mechanism could be used to imprint other target superpositions by choosing different atomic measurement bases or drive waveforms, potentially generating squeezed cats or grid states without extra nonlinear elements.
  • A natural experiment would be to implement the protocol in an existing dispersive cavity-QED platform and measure the Wigner function; observing the predicted checkerboard interference for the four-component state would confirm the recursive construction.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 4 minor

Summary. The manuscript proposes a conditional protocol for generating Schrödinger cat states in cavity QED by alternating coherent driving of the cavity, dispersive atom-cavity interaction, and atomic postselection in a superposition basis. For one cycle the authors derive the postselected two-component coherent-state superposition (Eq. (5)), and for repeated cycles they give a recursive relation (Eq. (9)) that they claim yields 2^N-component cats. They also present Lindblad master-equation simulations for two- and four-component states under cavity dissipation. The single-cycle derivation is correct, but the multi-component generalization is not: Eq. (7) is inconsistent with the stated cycle order and with Eq. (9), and the claimed 2^N-component scaling fails for the parameters used in the paper.

Significance. The two-component result is sound and the physical setting is standard and plausible; the use of atomic postselection as a non-Gaussian resource is a legitimate idea. The recursive relation (9) is also correctly derived as an amplitude recurrence. However, the central claimed advance is the scalable generation of 2^N-component cat states, and this claim is not supported. Because Eq. (7) is wrong, both the analytical four-component state and the associated dissipative simulations (Figs. 2(c), 3(b), 3(d)) do not describe the output of the protocol. The two-component protocol alone would be a modest, mostly known result (cf. Ref. [48]).

major comments (4)
  1. [Section III, Eq. (7)] Equation (7) does not follow from the drive-before-interaction cycle stated in Eq. (1) and used in Eq. (9). For a component with amplitude beta, one full cycle maps beta to (beta - i eta tau1) e^{± i chi tau2}, as in Eq. (9), but Eq. (7) uses amplitudes of the form -i eta tau1 e^{± i chi tau2} - i eta tau1 e^{± i chi tau2}, i.e., it applies the rotation to the new displacement rather than to the total amplitude. For chi tau2 = pi/2, Eq. (7) predicts the four amplitudes {-2 eta tau1, 0, 0, 2 eta tau1}, whereas Eq. (9) predicts the four amplitudes {eta tau1(±1 ± i)}. The probability amplitudes in Eq. (7) are also incorrect: the two middle terms should carry factors cos^2 theta sin^2 theta, not (1/4) sin^4(2 theta). Since Fig. 2(c) is presented as the Wigner function of the state in Eq. (7), that figure does not show the output of the described protocol.
  2. [Section III, Eqs. (8)-(9)] The recurrence doubles the number of terms in the superposition, not the number of distinct coherent-state components. With the parameters used throughout the paper, eta tau1 = 2 and chi tau2 = pi/2, starting from S_1 = {2, -2} gives S_2 = {2 ± 2i, -2 ± 2i} (four distinct components) and S_3 = {±2i, ±4 ± 2i} (six distinct components). The stated '2^N-component' scaling therefore fails for the paper's own parameter values, and the conclusion drawn from Eqs. (8)-(9) is unsupported.
  3. [Section III, after Eq. (9)] Even if a parameter choice avoided exact collisions, the scalable cat-state claim is problematic in the large-N limit. After N cycles every amplitude is a sum of N terms each of modulus eta tau1, so all components lie in a disk of radius O(N eta tau1). Placing 2^N components in a region whose area grows only polynomially in N forces the typical separation between components to shrink exponentially, so the components are not macroscopically distinguishable and the state is not a Schrödinger cat state in the usual sense.
  4. [Section IV] The dissipative simulations for the four-component cat state are presented as recovering the analytical solution of Eq. (7). Since Eq. (7) is not the state produced by the protocol, the claimed robustness of the four-component state (Figs. 3(b) and 3(d)) needs to be re-evaluated with the correct state from Eq. (9). The two-component dissipative results (Figs. 3(a) and 3(c)) are not affected by this criticism, but the multi-component robustness claim is.
minor comments (4)
  1. [References] Reference [29] contains a typo: 'H,-J, Xing' should read 'H.-J. Xing'.
  2. [Section III] The postselection success probability P_N and its scaling with N are not reported. For a conditional protocol, this quantity is essential for assessing practical scalability, especially because each successful postselection is expected to reduce the success probability.
  3. [Section III] The statement that the evolution 'remains Gaussian' is imprecise: the dispersive interaction is a controlled rotation, which is Gaussian on each conditional cavity branch; the non-Gaussianity is introduced by the projective postselection. This should be clarified.
  4. [Data availability] The data-availability statement says the data are not publicly available; for a numerical manuscript, providing the simulation code would strengthen reproducibility.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity; the protocol is a self-contained unitary-and-postselection derivation from the stated Hamiltonian.

full rationale

The paper's central claims are derived directly from the stated Hamiltonian in Eq. (1): resonant driving gives the coherent displacement in Eq. (3), the dispersive interaction produces the two branch amplitudes in Eq. (4), and atomic postselection in Eq. (5) is an explicit inner product that yields the coherent-state superposition. The multi-component recursion in Eqs. (8)-(9) is obtained by applying the same two operations (displacement followed by dispersive phase rotation) to each existing component, and it introduces no fitted parameters and does not define the protocol in terms of the target cat state. The Lindblad master-equation simulations in Sec. IV provide an independent numerical check rather than an input to the derivation. Citations to the prior cavity-QED literature support the validity of the dispersive Hamiltonian and experimental feasibility, but none carries the load of the derivation; the derivation would stand even if those citations were removed. The skeptical concern that some amplitudes may coincide for the chosen parameters (so the number of distinct coherent-state components need not be exactly 2^N) is a mathematical correctness issue about distinctness and macroscopic distinguishability, not a circularity, and therefore does not affect the circularity score.

Assumptions & free parameters 0 free parameters · 5 assumptions · 0 invented entities

The derivation assumes ideal dispersive coupling, perfect displacement, pure atomic states, and lossless projective postselection, with only cavity photon loss included. These are standard idealizations but are load-bearing for the claimed Wigner negativity and experimental accessibility.

assumptions (5)
  • domain assumption The dispersive Hamiltonian H_int = χ a†a σ_z is exact for the full interaction time τ2, with no atomic decay or other atomic decoherence.
    Used in Eq. (1) and in deriving Eq. (4). If the large-detuning approximation fails or the atom emits, the which-way information is not cleanly encoded and the postselected state is not a pure cat.
  • domain assumption The coherent drive acts as an ideal displacement operator D(-iητ1) with instantaneous switching on and off.
    Used in Eq. (3). Transient or imperfect switching would add noise and degrade the coherent-state branches.
  • domain assumption The atomic postselection is a perfect projective measurement onto the superposition state |ψ_f> with unity detection efficiency.
    Required for Eq. (5). Finite detection efficiency or measurement in a different basis would mix the cavity state and reduce Wigner negativity.
  • domain assumption The initial cavity state is the vacuum and each atom is prepared in the pure state cosθ|e> + sinθ|g>.
    Used in Section III to start the recursion. Thermal or mixed initial states would alter the generated state.
  • domain assumption The open-system dynamics is governed by the Lindblad master equation with only the cavity photon-loss channel, Eq. (2).
    The paper neglects atomic spontaneous emission, dephasing, and other decoherence channels, which are likely relevant in a real cavity-QED experiment.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Measurement-induced generation of Schr\"{o}dinger cat states in cavity QED." pith.science (2026). https://pith.science/paper/UDB37UKH

@misc{pith2026260804578,
  author       = {Pith},
  title        = {Pith review of: Measurement-induced generation of Schr\"odinger cat states in cavity QED},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/UDB37UKH}},
  note         = {Machine review of arXiv:2608.04578}
}
read the original abstract

Schr\"{o}dinger cat states, representing coherent superpositions of macroscopically distinguishable states, are indispensable nonclassical resources for continuous-variable quantum information processing. Existing generation protocols typically rely on strong nonlinear interactions, complicated control techniques, or engineered dissipation, posing challenges for experimental implementation. Here, we propose a simple measurement-based protocol for generating Schr\"{o}dinger cat states in a cavity-QED system by combining coherent driving, dispersive atom--cavity interactions, and atomic postselection. The atom--cavity interaction establishes coherent correlations between the atomic and photonic degrees of freedom, while the subsequent atomic postselection projects the cavity field onto a non-Gaussian superposition state with pronounced Wigner negativity. Numerical simulations based on the Lindblad master equation show that the generated Schr\"{o}dinger cat states remain robust against moderate cavity dissipation. Our results demonstrate that conditional atomic measurements provide an effective and experimentally accessible approach for preparing nonclassical cavity states without relying on strong optical nonlinearities or engineered dissipation.

Figures

Figures reproduced from arXiv: 2608.04578 by the authors.

Figure 1
Figure 1. A schematic diagram of the model used for generat [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Wigner functions of Schr¨odinger cat states witho [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Influence of dissipation on the Wigner func [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

65 extracted references · 51 canonical work pages

  1. [48]

    Opatrn´ y, G

    T. Opatrn´ y, G. Kurizki, and D.-G. Welsch, Improvement on teleportation of continuous variables by photon sub- traction via conditional measurement, Phys. Rev. A 61, 032302 (2000). 7

  2. [1]

    Center for Quantum Sciences and School of Physics, Northeast Normal University, Changchun 130024, China Schr¨ odinger cat states, representing coherent superposi tions of macroscopically distinguishable states, are indispensable nonclassical resources for cont inuous-variable quantum information pro- cessing. Existing generation protocols typically rely o...

  3. [2]

    Measurement-induced generation of Schr\"{o}dinger cat states in cavity QED

    A single-mode cavity with res- onance frequency ωa is coherently driven by a classical arXiv:2608.04578v1 [quant-ph] 5 Aug 2026 2 Figure 1. A schematic diagram of the model used for generat- ing the Schr¨ odinger cat state is shown in the figure. A series of two-level atoms which are prepared in the same initial sta te pass through a single-mode cavity one...

  4. [3]

    Zheng, J.-C

    X.-W. Zheng, J.-C. Zheng, X.-F. Pan, and P. Li, Quantum-enhanced sensing of bosonic modes with cat states, Phys. Rev. A 112, 032612 (2025)

  5. [4]

    As a result, the atom becomes entangled with the cavity field

    shows that the dispersive atom–cavity interac- tion splits the initial coherent state into two coherent- state branches with opposite phase rotations, each cor- related with a different atomic state. As a result, the atom becomes entangled with the cavity field. A pro- jective measurement in the {|e⟩, |g⟩} basis preserves the which-way information encoded i...

  6. [5]

    Buˇ zek, A

    V. Buˇ zek, A. Vidiella-Barranco, and P. L. Knight, Super- positions of coherent states: Squeezing and dissipation, Phys. Rev. A 45, 6570 (1992)

  7. [6]

    Yurke and D

    B. Yurke and D. Stoler, Generating quantum mechanical superpositions of macroscopically distinguishable state s via amplitude dispersion, Phys. Rev. Lett. 57, 13 (1986)

  8. [7]

    T. C. Ralph, A. Gilchrist, G. J. Milburn, W. J. Munro, and S. Glancy, Quantum computation with optical co- herent states, Phys. Rev. A 68, 042319 (2003)

Show all 65 references
  1. [8]

    Consequently, the number of coherent- state components doubles after every cycle, leading to the systematic generation of 2 N -component Schr¨ odinger cat states

    and (9) show that each coherent-state component generated in the nth cycle is deterministically split into two new components in the subsequent cycle. Consequently, the number of coherent- state components doubles after every cycle, leading to the systematic generation of 2 N ...

  2. [9]

    X. L. He, Y. Lu, D. Q. Bao, H. Xue, W. B. Jiang, Z. Wang, A. F. Roudsari, P. Delsing, J. S. Tsai, and Z. R. Lin, Fast generation of Schr¨ odinger cat states using a Kerr-tunable superconducting resonator, Nat. Commun. 14, 6358 (2023)

  3. [10]

    Zheng, Y

    P. Zheng, Y. Cai, B. Xu, S. Wen, L. Zhang, Z. Ni, J. Mai, et al. , Quantum-enhanced dark matter search using cat states, Phys. Rev. Lett. 136, 171002 (2026)

  4. [11]

    Jeong and M

    H. Jeong and M. S. Kim, Efficient quantum computation using coherent states, Phys. Rev. A 65, 042305 (2002)

  5. [12]

    N. Ofek, A. Petrenko, R. Heeres, P. Reinhold, Z. Leghtas, B. Vlastakis, Y. Liu, L. Frunzio, S. M. Girvin, L. Jiang, M. Mirrahimi, M. H. Devoret, and R. J. Schoelkopf, Ex- tending the lifetime of a quantum bit with error correc- tion in superconducting circuits, Nature 536, 441 (2016)

  6. [13]

    A. P. Lund, T. C. Ralph, and H. L. Haselgrove, Fault-Tolerant Linear Optical Quantum Computing with Coherent-State Qubits, Phys. Rev. Lett. 100, 030503 (2008)

  7. [14]

    P. T. Cochrane, G. J. Milburn, and W. J. Munro, Macroscopically distinct quantum-superposition states a s a bosonic code for amplitude damping, Phys. Rev. A 59, 2631 (1999)

  8. [15]

    Leghtas, G

    Z. Leghtas, G. Kirchmair, B. Vlastakis, R. J. Schoelkop f, M. H. Devoret, and M. Mirrahimi, Hardware-Efficient Autonomous Quantum Memory Protection, Phys. Rev. Lett. 111, 120501 (2013)

  9. [16]

    Mirrahimi, Z

    M. Mirrahimi, Z. Leghtas, V. V. Albert, S. Touzard, R. J. Schoelkopf, L. Jiang, and M. H. Devoret, Dynamically protected cat-qubits: a new paradigm for universal quan- tum computation, New J. Phys. 16, 045014 (2014). 6

  10. [17]

    Liao, J.-F

    J.-Q. Liao, J.-F. Huang, L. Tian, L.-M. Kuang, and C.- P. Sun, Generalized ultrastrong optomechanical-like cou- pling, Phys. Rev. A 101, 063802 (2020)

  11. [18]

    Yin, Y.-H

    X.-L. Yin, Y.-H. Zhou, and J.-Q. Liao, All-optical quan - tum simulation of ultrastrong optomechanics, Phys. Rev. A 105, 013504 (2022)

  12. [19]

    Vlastakis, G

    B. Vlastakis, G. Kirchmair, Z. Leghtas, S. E. Nigg, L. Frunzio, S. M. Girvin, M. Mirrahimi, M. H. Devoret, and R. J. Schoelkopf, Deterministically Encoding Quantum Information Using 100-Photon Schr¨ odinger Cat States, Science 342, 607 (2013)

  13. [20]

    L. Hu, Y. Ma, W. Cai, X. Mu, Y. Xu, W. Wang, Y. Wu, H. Wang, Y. P. Song, C.-L. Zou, S. M. Girvin, L.-M. Duan, and L. Sun, Quantum error correction and uni- versal gate set operation on a binomial bosonic logical qubit, Nat. Phys. 15, 503 (2019)

  14. [21]

    Chamberland, K

    C. Chamberland, K. Noh, P. Arrangoiz-Arriola, E. T. Campbell, A. M. Jiang, J. I. Papierman, H. M. Andrews, A. Filmer, and L. Jiang, Building a fault-tolerant quan- tum computer using concatenated cat codes, PRX Quan- tum 3, 010329 (2022)

  15. [22]

    Del´ eglise, I

    S. Del´ eglise, I. Dotsenko, C. Sayrin, J. Bernu, M. Brun e, J. M. Raimond, and S. Haroche, Reconstruction of non- classical cavity field states with snapshots of their deco- herence, Nature 455, 510 (2008)

  16. [23]

    J. S. Neergaard-Nielsen, Y. Eto, C.-W. Lee, H. Kondo, M. Zhang, and M. Sasaki, Quantum tele-amplification with a continuous-variable superposition state, Nat. Pho- tonics 7, 439 (2013)

  17. [24]

    S. L. Braunstein and P. van Loock, Quantum informa- tion with continuous variables, Rev. Mod. Phys. 77, 513 (2005)

  18. [25]

    Gilchrist, K

    A. Gilchrist, K. Nemoto, W. J. Munro, T. C. Ralph, S. Glancy, S. L. Braunstein, and G. J. Milburn, Schr¨ odinger cats and their power for quantum information processing, J. Opt. B: Quantum Semiclass. Opt. 6, S828 (2004)

  19. [26]

    Jeong, M

    H. Jeong, M. S. Kim, and J. Lee, Quantum-information processing for a coherent superposition state via a mixe- dentangled coherent channel, Phys. Rev. A 64, 052308 (2001)

  20. [27]

    W. J. Munro, K. Nemoto, G. J. Milburn, and S. L. Braunstein, Weak-force detection with superposed coher- ent states, Phys. Rev. A 66, 023819 (2002)

  21. [28]

    J. Joo, W. J. Munro, and T. P. Spiller, Quantum Metrol- ogy with Entangled Coherent States, Phys. Rev. Lett. 107, 083601 (2011)

  22. [29]

    M. Bild, M. Fadel, Y. Yang, U. von L¨ upke, P. Mar- tin, A. Bruno, and Y. Chu, Schr¨ odinger cat states of a 16-microgram mechanical oscillator, Science 380, 274 (2023)

  23. [30]

    Y. Liu, L. Qin, and X.-Q. Li, Fisher information anal- ysis on weak-value-amplification metrology using optical coherent states, Phys. Rev. A 106, 022619 (2022)

  24. [31]

    Tatsuta, Y

    M. Tatsuta, Y. Matsuzaki, and A. Shimizu, Quantum metrology with generalized cat states, Phys. Rev. A 100, 032318 (2019)

  25. [32]

    Huang, X

    J. Huang, X. Qin, H. Zhong, Y. Ke, and C. Lee, Quan- tum metrology with spin cat states under dissipation, Sci. Rep. 5, 17894 (2015)

  26. [33]

    C. Wang, W. Shan, J.-Q. Pan, and H,-J, Xing, Heisenberg-limited two-parameter estimation with weighted three-mode Schr¨ odinger cat states in a triple- well Bose-Einstein condensate system, Phys. Rev. A 113, 062606 (2026)

  27. [34]

    Miranowicz, R

    A. Miranowicz, R. Tana´ s, and S. Kielich, Generation of discrete superpositions of coherent states in the anhar- monic oscillator model, Quantum Opt. 2, 253 (1990)

  28. [35]

    Dakna, T

    M. Dakna, T. Anhut, T. Opatrn´ y, L. Kn¨ oll, and D.-G. Welsch, Generating Schr¨ odinger-cat-like states by means of conditional measurements on a beam splitter, Phys. Rev. A 55, 3184 (1997)

  29. [36]

    Takase, J

    K. Takase, J. Yoshikawa, W. Asavanant, M. Endo, and A. Furusawa, Generation of optical Schr¨ odinger cat states by generalized photon subtraction, Phys. Rev. A 103, 013710 (2021)

  30. [37]

    M. Endo, T. Nomura, T. Sonoyama, K. Takahashi, S. Takasu, D. Fukuda, T. Kashiwazaki, A. Inoue, T. Umeki, R. Nehra, P. Marek, R. Filip, K. Takase, W. Asavanant, and A. Furusawa, High-Rate Four Photon Subtraction from Squeezed Vacuum: Preparing Cat State for Optical Quantum Comp...

  31. [38]

    Ourjoumtsev, H

    A. Ourjoumtsev, H. Jeong, R. Tualle-Brouri, and P. Grangier, Generation of optical Schr¨ odinger cats from photon number states, Nature 448, 784 (2007)

  32. [39]

    J. S. Neergaard-Nielsen, B. M. Nielsen, C. Hettich, K. Mølmer, and E. S. Polzik, Generation of a superposition of odd photon number states for quantum information networks, Phys. Rev. Lett. 97, 083604 (2006)

  33. [40]

    Takahashi, K

    H. Takahashi, K. Wakui, S. Suzuki, M. Takeoka, K. Hayasaka, A. Furusawa, and M. Sasaki, Generation of large-amplitude coherent-state superposition via ancill a- assisted photon subtraction, Phys. Rev. Lett. 101, 233605 (2008)

  34. [41]

    Z.-Y. Zhou, C. Gneiting, W. Qin, J. Q. You, and F. Nori, Enhancing dissipative cat-state generation via nonequi- librium pump fields, Phys. Rev. A 106, 023714 (2022)

  35. [42]

    Z.-Y. Zhou, C. Gneiting, J. Q. You, and F. Nori, Gener- ating and detecting entangled cat states in dissipatively coupled degenerate optical parametric oscillators, Phys. Rev. A 104, 013715 (2021)

  36. [43]

    Leghtas, S

    Z. Leghtas, S. Touzard, I. M. Pop, A. Kou, B. Vlastakis, A. Petrenko, K. M. Sliwa, A. Narla, S. Shankar, M. J. Hatridge, M. Reagor, L. Frunzio, R. J. Schoelkopf, M. Mirrahimi, and M. H. Devoret, Confining the state of light to a quantum manifold by engineered two-photon loss, S...

  37. [44]

    S. J. de Graaf, S. H. Xue, B. J. Chapman, J. D. Teoh, et al. , A mid-circuit erasure check on a dual-rail cavity qubit using the joint-photon number-splitting regime of circuit QED, npj Quantum Inf. 11, 15 (2025)

  38. [45]

    A. M. Lance, H. Jeong, N. B. Grosse, T. Symul, T. C. Ralph, and P. K. Lam, Quantum-state engineering with continuous-variable postselection, Phys. Rev. A 73, 041801(R) (2006)

  39. [46]

    L. Sun, A. Petrenko, Z. Leghtas, B. Vlastakis, G. Kirch- mair, K. M. Sliwa, A. Narla, M. Hatridge, S. Shankar, J. Blumoff, L. Frunzio, M. Mirrahimi, M. H. Devoret, and R. J. Schoelkopf, Tracking photon jumps with repeated quantum non-demolition parity measurements, Nature 511, ...

  40. [47]

    X. Deng, Y. Cai, Z. Ni, L. Zhang, S. Liu, Y. Xu, and D. Yu, Generating and characterizing generalized squeezed states in a superconducting microwave cavity, Optica 13, 1334 (2026)

  41. [49]

    Eisert, S

    J. Eisert, S. Scheel, and M. B. Plenio, Distilling Gauss ian States with Gaussian Operations is Impossible, Phys. Rev. Lett. 89, 137903 (2002)

  42. [50]

    Weedbrook, S

    C. Weedbrook, S. Pirandola, R. Garc ´ ıa-Patr´ on, N. J. Cerf, T. C. Ralph, J. H. Shapiro, and S. Lloyd, Gaussian quantum information, Rev. Mod. Phys. 84, 621 (2012)

  43. [51]

    Yan, Z.-C

    K.-X. Yan, Z.-C. Shi, Y.-H. Chen, and Y. Xia, Con- trollable non-Hermiticity in continuous-variable qubits , Phys. Rev. A 113, 052406 (2026)

  44. [52]

    Schr¨ odinger cat

    M. Brune, S. Haroche, J. M. Raimond, L. Davidovich, and N. Zagury, Manipulation of photons in a cavity by dispersive atom-field coupling: Quantum-nondemolition measurements and generation of “Schr¨ odinger cat” states, Phys. Rev. A 45, 5193 (1992)

  45. [53]

    J. M. Raimond, M. Brune, and S. Haroche, Manipulat- ing quantum entanglement with atoms and photons in a cavity, Rev. Mod. Phys. 73, 565 (2001)

  46. [54]

    Guerlin, J

    C. Guerlin, J. Bernu,S. Del´ eglise, C. Sayrin, S. Gleyz es, S. Kuhr, M. Brune, J.-M. Raimond, and S. Haroche, Pro- gressive field-state collapse and quantum non-demolition photon counting, Nature 448, 889 (2007)

  47. [55]

    Cheng, S

    W. Cheng, S. C. Hou, Z. Wang, and X. X. Yi, Quantum metrology enhanced by coherence-induced driving in a cavity-QED setup, Phys. Rev. A 100, 053825 (2019)

  48. [56]

    M. O. Scully and K. Dr¨ uhl, Quantum eraser: A pro- posed photon correlation experiment concerning observa- tion and ”delayed choice” in quantum mechanics, Phys. Rev. A 25, 2208 (1982)

  49. [57]

    M. O. Scully, B.-G. Englert, and H. Walther, Quantum optical tests of complementarity, Nature 351, 111 (1991)

  50. [58]

    K. Liu, Y. Xu, W. Wang, S.-B. Zheng, and L. Sun, A twofold quantum delayed-choice experiment in a super- conducting circuit, Sci. Adv. 3, e1603159 (2017)

  51. [59]

    Blais, R.-S

    A. Blais, R.-S. Huang, A. Wallraff, S. M. Girvin, and R. J. Schoelkopf, Cavity quantum electrodynamics for superconducting electrical circuits: An architecture for quantum computation, Phys. Rev. A 69, 062320 (2004)

  52. [60]

    Krastanov, V

    S. Krastanov, V. V. Albert, C. Shen, C.-L. Zou, R. W. Heeres, B. Vlastakis, R. J. Schoelkopf, and L. Jiang, Uni- versal control of an oscillator with dispersive coupling to a qubit, Phys. Rev. A 92, 040303 (2015)

  53. [61]

    Lindblad, On the generators of quantum dynamical semigroups, Commun

    G. Lindblad, On the generators of quantum dynamical semigroups, Commun. Math. Phys. 48, 119 (1976)

  54. [62]

    Carmichael, An Open Systems Approach to Quantum Optics (Springer Berlin Heidelberg, 1993)

    H. Carmichael, An Open Systems Approach to Quantum Optics (Springer Berlin Heidelberg, 1993)

  55. [63]

    Royer, Wigner function as the expectation value of a parity operator, Phys

    A. Royer, Wigner function as the expectation value of a parity operator, Phys. Rev. A 15, 449 (1977)

  56. [64]

    S. M. Barnett and P. M. Radmore, Methods in Theoret- ical Quantum Optics (Clarendon Press, Oxford, 1997)

  57. [65]

    W. H. Zurek, Sub-Planck structure in phase space and its relevance for quantum decoherence, Nature 412, 712 (2001)

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.