Two-path interference of single-particle pulses measured by the Unruh-DeWitt-type quantum detector

Bo-Hung Chen; Dah-Wei Chiou; Tsung-Wei Chen

REVIEW 3 major objections 6 minor 36 references

Two-path interference of single-particle pulses measured by the Unruh-DeWitt-type quantum detector

T0 review · 3 major / 6 minor · reviewed 2026-08-14 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗ Review JSON

Pith's one-line read A time-coherent quantum detector reveals two-path interference even when the pulse's coherence length is far exceeded.

desk verdict The core UDW two-path interference calculation is clean and worth engaging with; the Sec. V classical-limit and objective-collapse claims are formal or interpretive overreach and should be read with care. read the letter →

arxiv 1908.07719 v4 pith:WHNWDKMA submitted 2019-08-21 quant-ph

Bo-Hung Chen , Tsung-Wei Chen , Dah-Wei Chiou This is my paper · ORCID

classification quant-ph

keywords two-pathinterferenceUnruh-DeWittdetectorsingle-particlepulseMach-Zehnderinterferometercoherencelengthquantummeasurementdecoherenceobjectivecollapse

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 claims that the disappearance of two-path interference for large path-length differences is not a fundamental property of the particle pulse, but a property of the detector. Using an idealized point-like two-level quantum detector (an Unruh-DeWitt detector) that interacts unitarily with a single-particle pulse in a Mach-Zehnder interferometer, it derives a detection probability that stays modulated by the path phase no matter how much the two paths differ in length, as long as the detector remains coherent in time during the arrival of both wave packets. The same calculation shows that an ensemble of such detectors with very short individual coherence times reproduces the familiar classical-detector result, with the interference exponentially damped. If correct, the result makes the distinction between classical and quantum detectors experimentally meaningful and supports the view that loss of time-coherence, not collapse by an observer, is what suppresses quantum interference.

What carries the argument

The machinery is the Unruh-DeWitt detector: an idealized point-like two-level system coupled to a scalar field through the monopole interaction Hamiltonian $H_{\rm int} = \kappa\chi(t)\mu(t)\varphi(0,t)$, with $\chi(t)$ a switching function. First-order perturbation theory expresses the transition amplitude as an integral of the Wightman function against the two arriving wave packets; the integration over time produces a resonance condition that selects a single wave number $k_*$ determined by the detector's energy gap, which is why the interference phase becomes $k_*\Delta L$ rather than $k_0\Delta L$. The switching function carries the physics of coherence: a long flat $\chi(t)=1$ window lets the two separated wave packets interfere within one detector, while a Gaussian $\chi(t)$ with random onset time $t_\chi$, when averaged over an ensemble, reproduces the classical detector's incoherent sum and its exponential suppression.

What would settle it

Measure two-path interference visibility with a well-isolated two-level quantum detector while sweeping the path difference $\Delta L$ from small values to far beyond the pulse coherence length, and independently verify that the detector coherence time satisfies $\delta t \gg \Delta L/v_0$; if the visibility still follows the classical exponential $e^{-(\Delta L/(2\sqrt{2}\Delta))^2}$ or the fringe phase is $k_0\Delta L$ rather than $k_*\Delta L$, the central claim is wrong.

Watch

Extended reading notes

Core claim

The paper's central result is the first-order transition probability of an Unruh-DeWitt detector placed after the recombining beam splitter: $P_{D1,D2} = \frac{1}{2}\left(1 \pm \cos(k_*\Delta L + \theta)\right) |A_0(k_*)|^2$, with $k_*$ fixed by the detector energy gap through $k_* = (\Delta E - \omega_0 + v_0 k_0)/v_0$. Unlike the classical detector probability, this expression contains no factor $e^{-(\Delta L/(2\sqrt{2}\Delta))^2}$, so the fringe pattern does not dim when the path difference $\Delta L$ greatly exceeds the pulse width $\Delta$. The required condition is that the detector's coherence time $\delta t$ satisfies $\Delta L \lesssim v_0\delta t$ and $\Delta \lesssim v_0\delta t$. The paper also derives the classical limit: when an ensemble of identical detectors is switched on with Gaussian windows of width $\Delta_\chi$ at uncorrelated random times, the ensemble-averaged probability reduces to the classical expression with exponential damping in the limit $v_0\Delta_\chi \ll \Delta$.

Load-bearing premise

The quantitative bridge from quantum to classical detection rests on modeling decoherence in time as a Gaussian switching function with uniformly random onset time and identifying its width with the detector's coherence time, so if real environmental decoherence acts differently, the interpolated exponential damping is not guaranteed even though the two extreme limits may survive.

Editorial extensions

If this is right

The coherence length of a single-particle source would not set an absolute limit on two-path interference: a time-coherent quantum detector can recover fringes for path differences far beyond the pulse coherence length.
A single quantum detector with corrupted time-coherence, for example one coupled to a high-precision clock that records arrival time, should accumulate counts like a low-efficiency classical detector.
The detector's energy gap determines the interference phase through $k_*$, so tuning the gap shifts the fringe pattern in a way that differs from the classical phase $k_0\Delta L$.
The strict form of Fermi's golden rule, which sums frequency modes without interference, becomes inadequate when the detector stays coherent long enough to interfere different modes.
The analysis provides a concrete model in which whether an interferometer shows wave or particle behavior can be changed by replacing one type of detector with another after the particle has entered the interferometer.

Reading between the lines

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

If the claim holds, the effective coherence length relevant to an interference experiment is detector-dependent, so textbook statements that attribute fringe visibility solely to the source spectrum should be qualified by the detector's time-coherence.
The same unitary detector model could be tested with matter-wave interferometry, where the detector is an internal electronic state of an atom rather than a photon counter; the predicted phase $k_*\Delta L$ would offer a direct observable signature.
A natural extension would be to replace the single detector with a sequence of weak measurements in time, which might interpolate continuously between the fully coherent result and the classical result without invoking random timing jitter as the decoherence mechanism.
An experiment with a well-isolated superconducting or quantum-dot qubit as the detector, sweeping $\Delta L$ while monitoring $\delta t$, could distinguish this timing-jitter model from other decoherence mechanisms because the exponential damping as a function of $\Delta\chi$ is specific.

Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

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

Desk Editor's Note

read the letter

Two things worth knowing. First, the core calculation is solid: a long-coherence Unruh-DeWitt detector interacting with a two-path Gaussian single-particle pulse gives (4.15), with interference at k*ΔL and no coherence-length damping. The route from first-order perturbation theory to that result is explicit, the approximations are stated, and the algebra holds up. Second, the paper's broader claims about objective-collapse theories and refuting the von Neumann-Wigner interpretation are not supported by the model. Those sections should not be bought as-is.

What is genuinely new: using a UDW detector as a coherent, broadband single-particle detector in a Mach-Zehnder interferometer, and showing that the detector's coherence time rather than the pulse coherence length controls the fringe visibility. The k* resonance condition and the explicit interpolation between quantum and classical limits are a useful combination. Appendix A is also valuable—it explains why the standard Fermi golden-rule rate sum misses inter-mode interference when the detector remains coherent longer than the separation between wave packets. That point is often glossed over and is worth having in print.

The soft spots are real but localized. The Sec. V classical limit is ad hoc: loss of time-coherence is modeled as a Gaussian switching function with a random switching time. There is no bath, no entanglement, and no derivation that environmental decoherence acts as timing jitter. The authors concede this, but then they lean on the result to say an ensemble of quantum detectors 'collectively behaves as a classical detector.' The two endpoints—long-coherence quantum and short-coherence classical—probably survive, but the quantitative interpolation, including the exponential factor, is a formal prescription rather than a microphysical result. The interpretive section goes further and claims support for objective collapse and refutation of von Neumann-Wigner. That is overreach: the calculation still requires a classical detector for the final readout, and it says nothing about spontaneous localization thresholds. The Schrödinger-cat framing is a thought experiment, not evidence.

Citation pattern is fine. The single self-citation is for a background remark, and the derivation uses no fitted parameters. No code or data, but none is needed for this kind of analytic calculation.

Who should read it: people working on UDW detectors, interferometry with weak or coherent detection, and the measurement problem as applied to detector models. It deserves a serious referee, and my recommendation would be major revision: keep the solid (4.15) result, mark Sec. V explicitly as a formal model of short coherence, and cut or heavily qualify the objective-collapse and von Neumann-Wigner conclusions.

Referee Report

3 major / 6 minor

Summary. The paper studies a Mach-Zehnder interferometer in which single-particle wave packets of a scalar field travel along two paths and are detected either by 'classical' detectors, modeled as projective time-incoherent devices, or by Unruh-DeWitt-type two-level quantum detectors. The central technical result is Eq. (4.15): for a detector whose coherence time is long enough to cover the arrivals of both wave packets, first-order perturbation theory gives a detection probability modulated as (1/2)[1 ± cos(k*ΔL + θ)] with no exponential suppression in the path-length difference ΔL, in contrast to the classical result (3.2). The paper then introduces a Gaussian switching function with randomly distributed switch-on times (5.1) and shows that an ensemble average over these times gives the quantum result in the long-switching limit (5.12) and the classical result in the short-switching limit (5.14). Sections VI and VII treat the two detectors jointly via POVMs and draw broad conclusions about decoherence and objective-collapse theories.

Significance. The derivation of (4.15) is self-contained, analytically explicit, and free of fitted parameters; it provides a concrete example where a coherent quantum detector recovers two-path interference between temporally separated pulses, with the phase determined by the energy-conserving wave vector k* rather than by the carrier wave vector k0. The POVM treatment in Sec. VI and the careful comparison with an etalon in Sec. V.A are useful clarifications. The classical-limit calculation in Sec. V is algebraically careful, but its physical foundation is a specific ad hoc model of 'coherence in time', and the paper's broader interpretive claims about objective-collapse theories go beyond what the calculation shows. If the authors revise the claims to match the model, the paper would be a valuable addition to the literature on detector coherence and interferometry.

major comments (3)

[Sec. V, Eq. (5.1) and (5.7)] The ensemble average over uniformly random Gaussian switch-on times tχ models timing jitter in the turning-on of the detector, not environmental decoherence of the detector's internal state. The paper explicitly states (Sec. V, final paragraph) that no underlying decoherence mechanism is formulated. Consequently, the identification Δχ ∼ δt and the quantitative classical limit (5.14), including the factor exp[-(ΔL/(2√2Δ))²], are not established for real decohered detectors. The two limiting cases (very long and very short switching) are plausible, but the interpolation in (5.10) depends on the specific Gaussian-random-jitter assumption. This is load-bearing for the abstract claim that an ensemble of quantum detectors 'collectively behaves as an ordinary classical detector' and for the Sec. VII discussion. The authors should either derive the classical limit from a microscopic decoherence model or explicitly restrict the claim to the formal switching model and temper the wording.
[Sec. VII (and Abstract/Introduction)] The statements that the model 'strongly supports the interpretation of quantum collapse in objective-collapse theories' and 'runs counter to the von Neumann-Wigner interpretation' are not supported by the calculation. The model is ordinary unitary quantum mechanics plus a projective final measurement; it does not include any spontaneous localization process. A difference between a coherent detector and a decohered detector follows from standard quantum mechanics and is not evidence for a particular collapse interpretation. These interpretive claims should be removed or explicitly labeled as speculation that the model cannot address.
[Sec. IV A, Eq. (4.18)] The conditions ΔL ≲ v0δt and Δ ≲ v0δt are stated as requirements for (4.15) to hold, but δt is not defined dynamically in Sec. IV; it is only connected to the switching width Δχ in Sec. V via the same ad hoc model criticized above. The paper should either define δt through the model's Hamiltonian and environment or present (4.18) as a heuristic condition rather than a derived one.

minor comments (6)

[Sec. V, Eq. (5.2)] The Gaussian factor is written as exp[-(t-tχ)²/(2Δχ²)] after the change of variables t'=t; it should be exp[-(t'-tχ)²/(2Δχ²)] for consistency with Eq. (5.4).
[Sec. IV A, last paragraph] The word 'pathes' should be 'paths'.
[Sec. V, first paragraph] The word 'constat' should be 'constant'.
[Fig. 1 caption] The phrase 'phase-shit plate' should be 'phase-shift plate'.
[Sec. V.A, Eq. (5.17)] The label '(wrong!)' is unusual for a journal and could be replaced by a descriptive phrase such as '(corrected below)'.
[Sec. V, paragraph before Eq. (5.7)] The use of L for the random-time delimiter conflicts with the path lengths L1 and L2; consider renaming it to T or L_av to avoid confusion.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the central quantum-detector interference result is derived from stated first-order perturbation inputs, and the only self-citation is a non-load-bearing background remark.

full rationale

The paper's central result, Eq. (4.15), is obtained by a self-contained first-order perturbative calculation starting from the Unruh-DeWitt interaction Hamiltonian (4.1), the Gaussian single-particle pulse (2.4), and the Wightman function (4.10). The parameters κ, ΔE, k0, and Δ are inputs; none are fitted to the target interference probability, and the derivation does not invoke the classical result (3.2) as an input. The classical detector probability (3.2) is introduced independently via the incoherent time sum (3.1), and is not used to derive the quantum result. The only place where a concern could arise is Sec. V, where the Gaussian switching function with uniformly random tχ (5.1) is used to model short coherence in time. In the limit v0Δχ ≪ Δ, the ensemble average indeed reproduces the classical expression (3.2) as (5.14). However, this is an explicitly stated formal model, not a hidden reuse of the target: the paper says 'we do not attempt to formulate the underlying mechanism of quantum decoherence' and instead 'formally reduc[es] the time span of the switching function.' The random-tχ ansatz encodes 'no coherence in time' by construction, so recovering the classical incoherent sum is a consistency check of the model rather than an independent microscopic derivation; this is a modeling limitation that bears on physical applicability, not circularity in the derivation. The one self-citation, Ref. [28] by author D.-W. Chiou, appears in footnote 18 for a general remark about the implicit long-coherence assumption in the Unruh-DeWitt effect; it is not load-bearing because the paper's own calculation demonstrates the same point. No uniqueness theorem from the authors' prior work is invoked, no fitted parameter is relabeled as a prediction, and no known result is merely renamed. The central claim (4.15) stands on its own derivation.

Assumptions & free parameters 1 free parameters · 4 assumptions · 0 invented entities

The central derivation has no fitted parameters and rests on standard QFT and first-order perturbation theory. The only ad hoc ingredient is the Gaussian switching function model for decoherence in time, which is used for the classical-detector limit. The UDW detector and monopole interaction are idealized models; real photodetection uses different couplings, which the authors argue do not change the qualitative result.

free parameters (1)

coherence time delta_t (switching width delta_chi)
Introduced by hand in Sec. IV.A and Sec. V to model the detector's coherence in time and to interpolate between quantum and classical limits. The Gaussian form (5.1) is an ad hoc prescription, not derived from a microphysical decoherence model.

assumptions (4)

standard math First-order time-dependent perturbation theory applies to the UDW detector interaction
Used throughout Sec. IV to compute transition amplitudes, requiring the coupling κ and total transition probability to be small.
domain assumption The scalar Klein-Gordon field and UDW monopole interaction model the single-particle pulse and detector
The detector is idealized as a two-level UDW detector (Eq. (4.1)); real photodetection involves M1 transitions (Appendix A), which the authors argue does not change the qualitative result.
domain assumption The classical detector's total detection probability is the time-integrated intensity
Eq. (3.1) assumes P ∝ ∫|F(0,t)|^2 dt; this is the standard photodetection model and is the baseline against which the quantum detector is compared.
ad hoc to paper Decoherence in time can be modeled by a Gaussian switching function with random switch-on times
Eq. (5.1) and the ensemble average in Sec. V; the authors themselves call this a 'formal prescription' and do not derive it from environmental dynamics.

how reviews work

0 comments

Cite this review

Pith. "Pith review of Two-path interference of single-particle pulses measured by the Unruh-DeWitt-type quantum detector." pith.science (2026). https://pith.science/paper/WHNWDKMA

@misc{pith2026190807719,
  author       = {Pith},
  title        = {Pith review of: Two-path interference of single-particle pulses measured by the Unruh-DeWitt-type quantum detector},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/WHNWDKMA}},
  note         = {Machine review of arXiv:1908.07719}
}

read the original abstract

We study the two-path interference of single-particle pulses measured by the Unruh-DeWitt-type quantum detector, which itself is a quantum state as well as the incoming pulse, and of which the interaction with the pulse is described by unitary quantum evolution instead of a nonunitary collapsing process. Provided that the quantum detector remains coherent in time long enough, the detection probability still manifests the two-path interference pattern even if the length difference between the two paths considerably exceeds the coherence length of the single-particle pulse, contrary to the result measured by an ordinary classical detector. Furthermore, it is formally shown that an ensemble of identical Unruh-DeWitt-type quantum detectors collectively behaves as an ordinary classical detector, if coherence in time of each individual quantum detector becomes sufficiently short. Our study provides a concrete yet manageable theoretical model to investigate the two-path interference measured by a quantum detector and facilitates a quantitative analysis of the difference between classical and quantum detectors. The analysis affirms the main idea of decoherence theory: quantum behavior is lost as a result of quantum decoherence.

Figures

Figures reproduced from arXiv: 1908.07719 by the authors.

**Figure 2.** FIG. 2. Schematic representations of the squared amplitude [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

36 extracted references · 36 canonical work pages

[1]

Law without law,

J. A. Wheeler, “Law without law,” in Quantum Theory and Measurement (J. A. Wheeler and W. H. Zurek, eds.), pp. 182–213, Princeton University Press, 1983. 17

work page 1983
[2]

classical cat

and then BSout splits the pulse coming from Path1 or Path2 equally to D1 and D2 (thus giving another factor of 1/slash.left √ 2), and furthermore an extra phaseeik0∆L is added to the wave function trav- eling along Path2. Because the two wave functions travel along diﬀerent lengths but the recombined result is cast in terms of the same coordinate y, we ha...

work page
[3]

Re- sults of the delayed-random-choice quantum mechanics experiment with light quanta,

C. O. Alley, O. G. Jakubowicz, and W. C. Wickes, “Re- sults of the delayed-random-choice quantum mechanics experiment with light quanta,” in Proceedings of the 2nd International Symposium on Foundations of Quantum Mechanics, Tokyo, p. 36, 1986

work page 1986
[4]

Delayed-choice experiments in quantum interference,

T. Hellmuth, H. Walther, A. Zajonc, and W. Schleich, “Delayed-choice experiments in quantum interference,” Physical Review A, vol. 35, no. 6, p. 2532, 1987

work page 1987
[5]

A wave-particle delayed-choice experiment with a single- photon state,

J. Baldzuhn, E. Mohler, and W. Martienssen, “A wave-particle delayed-choice experiment with a single- photon state,” Zeitschrift f¨ ur Physik B Condensed Mat- ter, vol. 77, no. 2, pp. 347–352, 1989

work page 1989
[6]

Delayed choices in atom Stern-Gerlach interferometry,

B. Lawson-Daku, R. Asimov, O. Gorceix, C. Miniatura, J. Robert, and J. Baudon, “Delayed choices in atom Stern-Gerlach interferometry,” Physical Review A, vol. 54, no. 6, p. 5042, 1996

work page 1996
[7]

Delayed ‘choice’ quantum eraser,

Y.-H. Kim, R. Yu, S. P. Kulik, Y. Shih, and M. O. Scully, “Delayed ‘choice’ quantum eraser,” Physical Review Let- ters, vol. 84, no. 1, p. 1, 2000

work page 2000
[8]

Realization of a delayed choice experiment using a multilayer cold neutron pulser,

T. Kawai, T. Ebisawa, S. Tasaki, M. Hino, D. Ya- mazaki, T. Akiyoshi, Y. Matsumoto, N. Achiwa, and Y. Otake, “Realization of a delayed choice experiment using a multilayer cold neutron pulser,” Nuclear Instru- ments and Methods in Physics Research Section A: Accel- erators, Spectrometers, Detectors and Associated Equip- ment, vol. 410, no. 2, pp. 259–263, 1998

work page 1998

Show all 36 references

[9]

Experimental realization of Wheeler’s delayed-choice gedanken experiment,

V. Jacques, E. Wu, F. Grosshans, F. Treussart, P. Grang- ier, A. Aspect, and J.-F. Roch, “Experimental realization of Wheeler’s delayed-choice gedanken experiment,” Sci- ence, vol. 315, no. 5814, pp. 966–968, 2007

2007
[10]

Notes on black-hole evaporation,

W. G. Unruh, “Notes on black-hole evaporation,” Phys- ical Review D, vol. 14, no. 4, p. 870, 1976

1976
[11]

Quantum gravity: the new synthesis,

B. S. DeWitt, “Quantum gravity: the new synthesis,” in General Relativity: an Einstein Centenary Survey (S. W. Hawking and W. Israel, eds.), Cambridge Uni- versity Press, 1979

1979
[12]

N. D. Birrell and P. C. W. Davies, Quantum Fields in Curved Space. Cambridge University Press, 1984

1984
[13]

R. M. Wald, Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics . University of Chicago press, 1994

1994
[14]

Gravity and the thermodynamics of horizons,

T. Padmanabhan, “Gravity and the thermodynamics of horizons,” Physics Reports, vol. 406, no. 2, pp. 49–125, 2005

2005
[15]

The Unruh eﬀect and its applications,

L. C. Crispino, A. Higuchi, and G. E. Matsas, “The Unruh eﬀect and its applications,” Reviews of Modern Physics, vol. 80, no. 3, p. 787, 2008

2008
[16]

A model for a uniﬁed quantum description of macroscopic and mi- croscopic systems,

G. C. Ghirardi, A. Rimini, and T. Weber, “A model for a uniﬁed quantum description of macroscopic and mi- croscopic systems,” in Quantum Probability and Applica- tions II, pp. 223–232, Springer, 1985

1985
[17]

Uniﬁed dy- namics for microscopic and macroscopic systems,

G. C. Ghirardi, A. Rimini, and T. Weber, “Uniﬁed dy- namics for microscopic and macroscopic systems,” Phys- ical Review D, vol. 34, no. 2, p. 470, 1986

1986
[18]

Markov pro- cesses in Hilbert space and continuous spontaneous local- ization of systems of identical particles,

G. C. Ghirardi, P. Pearle, and A. Rimini, “Markov pro- cesses in Hilbert space and continuous spontaneous local- ization of systems of identical particles,” Physical Review A, vol. 42, no. 1, p. 78, 1990

1990
[19]

On gravity’s role in quantum state reduc- tion,

R. Penrose, “On gravity’s role in quantum state reduc- tion,” General relativity and gravitation , vol. 28, no. 5, pp. 581–600, 1996

1996
[20]

Quantum computation, entanglement and state reduction,

R. Penrose, “Quantum computation, entanglement and state reduction,” Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, vol. 356, no. 1743, pp. 1927–1939, 1998

1927
[21]

On the gravitization of quantum mechanics 1: Quantum state reduction,

R. Penrose, “On the gravitization of quantum mechanics 1: Quantum state reduction,” Foundations of Physics , vol. 44, no. 5, pp. 557–575, 2014

2014
[22]

A conjecture concerning determinism, reduc- tion, and measurement in quantum mechanics,

A. Jabs, “A conjecture concerning determinism, reduc- tion, and measurement in quantum mechanics,” Quan- tum Studies: Mathematics and Foundations , vol. 3, no. 4, pp. 279–292, 2016

2016
[23]

von Neumann, Mathematical foundations of quantum mechanics: New edition

J. von Neumann, Mathematical foundations of quantum mechanics: New edition . Princeton university press, 2018

2018
[24]

The problem of measurement,

E. P. Wigner, “The problem of measurement,” American Journal of Physics , vol. 31, no. 1, pp. 6–15, 1963

1963
[25]

M. E. Peskin and D. V. Schroeder, An Introduction to Quantum Field Theory . CRC Press, 2018

2018
[26]

Menzel, Photonics: Linear and Nonlinear Interactions of Laser Light and Matter

R. Menzel, Photonics: Linear and Nonlinear Interactions of Laser Light and Matter . Springer Science & Business Media, 2013

2013
[27]

Decoherence, the measurement prob- lem, and interpretations of quantum mechanics,

M. Schlosshauer, “Decoherence, the measurement prob- lem, and interpretations of quantum mechanics,”Reviews of Modern physics , vol. 76, no. 4, p. 1267, 2005

2005
[28]

Why decoherence has not solved the mea- surement problem: a response to PW Anderson,

S. L. Adler, “Why decoherence has not solved the mea- surement problem: a response to PW Anderson,” Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics , vol. 34, no. 1, pp. 135–142, 2003

2003
[29]

Response of the Unruh-DeWitt detector in ﬂat spacetime with a compact dimension,

D.-W. Chiou, “Response of the Unruh-DeWitt detector in ﬂat spacetime with a compact dimension,” Physical Review D, vol. 97, no. 12, p. 124028, 2018

2018
[30]

Signiﬁcance of electromag- netic potentials in the quantum theory,

Y. Aharonov and D. Bohm, “Signiﬁcance of electromag- netic potentials in the quantum theory,”Physical Review, vol. 115, no. 3, p. 485, 1959

1959
[31]

A test of a new type of stel- lar interferometer on Sirius,

R. H. Brown and R. Twiss, “A test of a new type of stel- lar interferometer on Sirius,” Nature, vol. 178, no. 4541, pp. 1046–1048, 1956

1956
[32]

Interferometry of the intensity ﬂuctuations in light. I. Basic theory: the corre- lation between photons in coherent beams of radiation,

R. H. Brown and R. Q. Twiss, “Interferometry of the intensity ﬂuctuations in light. I. Basic theory: the corre- lation between photons in coherent beams of radiation,” Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences , vol. 242, no. 1230...

1957
[33]

Interferometry of the in- tensity ﬂuctuations in light. II. An experimental test of the theory for partially coherent light,

R. H. Brown and R. Twiss, “Interferometry of the in- tensity ﬂuctuations in light. II. An experimental test of the theory for partially coherent light,” Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, vol. 243, no. 1234, pp. 291–319, 1958

1958
[34]

Single-photon sources and detectors (invited review article),

M. Eisaman, J. Fan, A. Migdall, and S. Polyakov, “Single-photon sources and detectors (invited review article),” Review of Scientiﬁc Instruments , vol. 82, pp. 071101–25, 2011

2011
[35]

J. J. Sakurai, Advanced Quantum Mechanics , Addison- Wesley, 1968

1968
[36]

Shankar, Principles of Quantum Mechanics , 2nd ed., Plenum Press, New York, 1994

R. Shankar, Principles of Quantum Mechanics , 2nd ed., Plenum Press, New York, 1994

1994

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.

[1] [1]

Law without law,

J. A. Wheeler, “Law without law,” in Quantum Theory and Measurement (J. A. Wheeler and W. H. Zurek, eds.), pp. 182–213, Princeton University Press, 1983. 17

work page 1983

[2] [2]

classical cat

and then BSout splits the pulse coming from Path1 or Path2 equally to D1 and D2 (thus giving another factor of 1/slash.left √ 2), and furthermore an extra phaseeik0∆L is added to the wave function trav- eling along Path2. Because the two wave functions travel along diﬀerent lengths but the recombined result is cast in terms of the same coordinate y, we ha...

work page

[3] [3]

Re- sults of the delayed-random-choice quantum mechanics experiment with light quanta,

C. O. Alley, O. G. Jakubowicz, and W. C. Wickes, “Re- sults of the delayed-random-choice quantum mechanics experiment with light quanta,” in Proceedings of the 2nd International Symposium on Foundations of Quantum Mechanics, Tokyo, p. 36, 1986

work page 1986

[4] [4]

Delayed-choice experiments in quantum interference,

T. Hellmuth, H. Walther, A. Zajonc, and W. Schleich, “Delayed-choice experiments in quantum interference,” Physical Review A, vol. 35, no. 6, p. 2532, 1987

work page 1987

[5] [5]

A wave-particle delayed-choice experiment with a single- photon state,

J. Baldzuhn, E. Mohler, and W. Martienssen, “A wave-particle delayed-choice experiment with a single- photon state,” Zeitschrift f¨ ur Physik B Condensed Mat- ter, vol. 77, no. 2, pp. 347–352, 1989

work page 1989

[6] [6]

Delayed choices in atom Stern-Gerlach interferometry,

B. Lawson-Daku, R. Asimov, O. Gorceix, C. Miniatura, J. Robert, and J. Baudon, “Delayed choices in atom Stern-Gerlach interferometry,” Physical Review A, vol. 54, no. 6, p. 5042, 1996

work page 1996

[7] [7]

Delayed ‘choice’ quantum eraser,

Y.-H. Kim, R. Yu, S. P. Kulik, Y. Shih, and M. O. Scully, “Delayed ‘choice’ quantum eraser,” Physical Review Let- ters, vol. 84, no. 1, p. 1, 2000

work page 2000

[8] [8]

Realization of a delayed choice experiment using a multilayer cold neutron pulser,

T. Kawai, T. Ebisawa, S. Tasaki, M. Hino, D. Ya- mazaki, T. Akiyoshi, Y. Matsumoto, N. Achiwa, and Y. Otake, “Realization of a delayed choice experiment using a multilayer cold neutron pulser,” Nuclear Instru- ments and Methods in Physics Research Section A: Accel- erators, Spectrometers, Detectors and Associated Equip- ment, vol. 410, no. 2, pp. 259–263, 1998

work page 1998