pith. sign in

arxiv: 2604.17767 · v1 · submitted 2026-04-20 · 🪐 quant-ph · physics.optics

Measurement-defined control of single-particle interference

Tai Hyun Yoon This is my paper

Pith reviewed 2026-05-10 05:20 UTC · model grok-4.3

classification 🪐 quant-ph physics.optics
keywords single-particle interferencemeasurement-defined basisbiphoton sourcesidler-state overlapfringe visibilityquantum distinguishabilitybright-dark states
0
0 comments X

The pith

Single-particle interference is governed by the relative phase between the prepared quantum state and the detector-defined measurement basis rather than path differences alone.

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

The paper demonstrates that single-particle interference patterns arise from the relative phase between the source-prepared quantum state and the basis states selected by the detector. This joint phase cannot be accessed or controlled in any conventional two-mode interferometer. Using coherently seeded entangled biphoton sources, the authors find that independently varying the pump phase, the seed phase, or the signal interferometric phase each produces identical sinusoidal fringes with visibility near 0.99. Visibility is tuned directly by the overlap of the undetected idler state, which encodes path distinguishability. The same measurement-defined law holds from the single-photon regime to high flux and unifies coherent population trapping, electromagnetically induced transparency, discrete photonic interference, and single-slit diffraction as cases differing only in the dimension of the dark subspace.

Core claim

Using coherently seeded entangled nonlinear biphoton sources, we demonstrate that single-particle interference is governed by the relative phase between the prepared quantum state and the detector-defined measurement basis. Independently scanning the pump phase difference, the seed phase difference, or the signal interferometric phase produces identical sinusoidal fringes with visibility approximately 0.99, a three-scan equivalence impossible in any two-mode interferometer. The fringe visibility is continuously controlled through the idler-state overlap, which directly encodes quantum distinguishability without requiring idler detection, and the same measurement-defined interference law is a

What carries the argument

the relative phase between the prepared quantum state and the detector-defined measurement basis, which sets the observed interference pattern and visibility

If this is right

  • Three independent phase scans (pump, seed, signal) produce identical high-visibility sinusoidal fringes.
  • Fringe visibility is tuned continuously by idler-state overlap that encodes distinguishability without idler detection.
  • The interference law remains unchanged from single-photon to high-flux regimes.
  • The bright-dark collective-state structure unifies coherent population trapping, EIT, photonic interference, and single-slit diffraction differing only in dark-subspace dimensionality.

Where Pith is reading between the lines

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

  • Measurement settings could be used to control effective phases in interference experiments without direct manipulation of source or path parameters.
  • The framework may allow reinterpretation of other interference phenomena as cases of engineered detector bases.
  • In device design this suggests phase control can be offloaded to the measurement stage rather than the source stage.

Load-bearing premise

The three-scan equivalence of identical fringes cannot occur in any conventional two-mode interferometer.

What would settle it

Observing non-identical fringe patterns or visibilities when independently scanning the pump phase versus the signal interferometric phase in the same seeded biphoton setup would disprove the claim.

Figures

Figures reproduced from arXiv: 2604.17767 by Tai Hyun Yoon.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
read the original abstract

Interference is conventionally attributed to path-accumulated phase differences, with measurement treated as a passive readout. Here we demonstrate that single-particle interference is governed by the relative phase between the prepared quantum state and the detector-defined measurement basis -- a joint quantity that is operationally inaccessible in any conventional interferometer. Using coherently seeded entangled nonlinear biphoton sources, we show that independently scanning the pump phase difference, the seed phase difference, or the signal interferometric phase each produces identical sinusoidal fringes ($V\approx0.99$) -- a three-scan equivalence impossible in any two-mode interferometer. The fringe visibility is continuously controlled through the idler-state overlap, directly encoding quantum distinguishability without idler detection. The same measurement-defined interference law persists from the single-photon to the high-flux regime. The bright-dark collective-state structure demonstrated here unifies coherent population trapping and electromagnetically induced transparency in atomic $\Lambda$-systems, discrete photonic interference, and single-slit diffraction within a common framework differing only in dark-subspace dimensionality, establishing measurement-defined photonic modes as a fundamental resource for quantum photonics.

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 manuscript claims that single-particle interference is governed by the relative phase between the prepared quantum state and the detector-defined measurement basis, a joint quantity operationally inaccessible in conventional interferometers. Using coherently seeded entangled biphoton sources, it demonstrates that independently scanning the pump phase difference, seed phase difference, or signal interferometric phase each yields identical high-visibility sinusoidal fringes (V≈0.99). Fringe visibility is controlled via idler-state overlap, encoding distinguishability without idler detection. This three-scan equivalence is asserted to be impossible in any two-mode interferometer. The same law holds from single-photon to high-flux regimes, and the bright-dark collective-state structure unifies CPT, EIT, discrete photonic interference, and single-slit diffraction, differing only in dark-subspace dimensionality, positioning measurement-defined photonic modes as a fundamental resource.

Significance. If substantiated, the result offers a useful re-framing of interference control in quantum optics by highlighting the active role of the detector-defined basis. The experimental realization with seeded biphoton sources and continuous visibility tuning via idler overlap is a concrete strength, as is the unification across CPT/EIT and photonic phenomena under a common collective-state model. These elements could aid conceptual organization in quantum photonics, though the operational-inaccessibility claim largely recasts standard distinguishability without introducing new falsifiable predictions beyond the reported equivalence.

major comments (1)
  1. Abstract: the assertion that the governing quantity is 'operationally inaccessible in any conventional interferometer' and that the three-scan equivalence is 'impossible in any two-mode interferometer' requires an explicit side-by-side derivation or counter-example showing why a suitably chosen two-mode basis cannot reproduce the observed equivalence; without this, the claim risks being definitional rather than a load-bearing physical distinction.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading of our manuscript and for recommending minor revision. We address the major comment below.

read point-by-point responses

  1. Referee: [—] Abstract: the assertion that the governing quantity is 'operationally inaccessible in any conventional interferometer' and that the three-scan equivalence is 'impossible in any two-mode interferometer' requires an explicit side-by-side derivation or counter-example showing why a suitably chosen two-mode basis cannot reproduce the observed equivalence; without this, the claim risks being definitional rather than a load-bearing physical distinction.

    Authors: We appreciate the referee's suggestion and agree that providing an explicit comparison will strengthen the presentation. In a conventional two-mode interferometer, such as a Mach-Zehnder, the interference arises solely from the relative phase accumulated along the two paths, which is controlled by a single parameter (the path length difference). There are no independent phases analogous to the pump phase difference (which sets the phase in the nonlinear interaction for pair generation) or the seed phase difference (the phase of the coherent seed beam injected into the source). Consequently, one cannot perform independent scans of three distinct phases that each produce equivalent high-visibility fringes. The measurement basis is defined by the output ports, but the prepared state phase is directly linked to the same path difference, making the joint quantity accessible via the path scan alone. In contrast, our seeded biphoton setup introduces additional degrees of freedom through the entanglement and coherent seeding, allowing the three independent controls. We will add a concise side-by-side derivation in the revised version, likely as an appendix, to show mathematically why a two-mode basis cannot replicate this three-scan equivalence. This will also clarify the operational inaccessibility in conventional setups. revision: yes

Circularity Check

0 steps flagged

No significant circularity

full rationale

The paper's central results rest on experimental observations of three-scan equivalence in a coherently seeded biphoton source, with visibility controlled by idler overlap, and a collective-state model that reproduces the data while unifying CPT/EIT and diffraction. No load-bearing derivation step reduces by construction to a fitted parameter, self-citation, or definitional renaming; the 'operationally inaccessible' framing is a consistent re-description of standard distinguishability without idler detection, and the impossibility claim for two-mode interferometers is asserted from the observed equivalence rather than derived circularly from prior self-work. The manuscript is self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

The central claim rests on standard quantum-optics assumptions about biphoton generation and linear interferometry plus the interpretive step that the governing phase is a joint state-measurement quantity.

axioms (1)
  • standard math Standard assumptions of quantum mechanics and linear optics for coherent seeding and entanglement in nonlinear crystals
    Invoked to interpret the phase scans and idler overlap as controlling visibility.
invented entities (1)
  • measurement-defined photonic modes no independent evidence
    purpose: To provide a common framework for interference, coherent population trapping, EIT, and diffraction
    Introduced as a fundamental resource differing only in dark-subspace dimensionality; no independent falsifiable prediction supplied in the abstract.

pith-pipeline@v0.9.0 · 5476 in / 1353 out tokens · 35059 ms · 2026-05-10T05:20:00.157205+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

31 extracted references · 2 canonical work pages · 1 internal anchor

  1. [1]

    Young, The Bakerian lecture: on the theory of light and colours, Philos

    T. Young, The Bakerian lecture: on the theory of light and colours, Philos. Trans. R. Soc. London92, 12 (1802)

  2. [2]

    Colella, A

    R. Colella, A. W. Overhauser, and S. A. Werner, Obser- vation of gravitationally induced quantum interference, Phys. Rev. Lett.34, 1472 (1975)

    1975

  3. [3]

    P. A. M. Dirac,The Principles of Quantum Mechanics, 4th ed. (Oxford University Press, Oxford, 1958)

    1958

  4. [4]

    Bohr, The quantum postulate and the recent develop- ment of atomic theory, Nature121, 580 (1928)

    N. Bohr, The quantum postulate and the recent develop- ment of atomic theory, Nature121, 580 (1928)

    1928

  5. [5]

    R. P. Feynman, R. B. Leighton, and M. Sands,The Feynman Lectures on Physics, Vol. III (Addison-Wesley, 1965)

    1965

  6. [6]

    Tonomura, J

    A. Tonomura, J. Endo, T. Matsuda, T. Kawasaki, and H. Ezawa, Demonstration of single-electron buildup of an interference pattern, Am. J. Phys.57, 117 (1989)

    1989

  7. [7]

    Riehle, T

    F. Riehle, T. Kisters, A. Witte, J. Helmcke, and C. J. Bord´ e, Optical Ramsey spectroscopy in a rotating frame: Sagnac effect in a matter-wave interferometer, Phys. Rev. Lett.67, 177 (1991)

    1991

  8. [8]

    Heisenberg, ¨Uber den anschaulichen Inhalt der quan- tentheoretischen Kinematik und Mechanik, Z

    W. Heisenberg, ¨Uber den anschaulichen Inhalt der quan- tentheoretischen Kinematik und Mechanik, Z. Phys.43, 172 (1927)

    1927

  9. [9]

    W. H. Zurek, Decoherence, einselection, and the quan- tum origins of the classical, Rev. Mod. Phys.75, 715 (2003)

    2003

  10. [10]

    R. J. Glauber, The quantum theory of optical coherence, Phys. Rev.130, 2529 (1963)

    1963

  11. [11]

    C. J. Villas-Boas, C. E. M´ aximo, P. J. Paulino, R. P. Bachelard, and G. Rempe, Bright and dark states of light: The quantum origin of classical interference, Phys. Rev. Lett.134, 133603 (2025)

    2025

  12. [12]

    Arimondo, Coherent population trapping in laser spec- troscopy, inProgress in Optics, Vol

    E. Arimondo, Coherent population trapping in laser spec- troscopy, inProgress in Optics, Vol. 35, edited by E. Wolf (Elsevier, Amsterdam, 1996) pp. 257–354

    1996

  13. [13]

    Aspect, E

    A. Aspect, E. Arimondo, R. Kaiser, N. Vansteenkiste, and C. Cohen-Tannoudji, Laser cooling below the one- photon recoil energy by velocity-selective coherent pop- ulation trapping, Phys. Rev. Lett.61, 826 (1988)

    1988

  14. [14]

    Qian and G

    X.-F. Qian and G. S. Agarwal, Quantum duality: A source point of view, Phys. Rev. Research2, 012031 (2020)

    2020

  15. [15]

    T. H. Yoon and M. Cho, Quantitative complementarity of wave-particle duality, Sci. Adv.7, eabi9268 (2021)

    2021

  16. [16]

    The Quantum Origin of Diffraction from Bright and Dark States

    J.-J. Cheng, J.-L. Che, L. Zhang, and M.-L. Hu, The quantum origin of diffraction from bright and dark states, arXiv:2510.16329 10.48550/arXiv.2510.16329 (2025)

    work page internal anchor Pith review Pith/arXiv arXiv doi:10.48550/arxiv.2510.16329 2025

  17. [17]

    delayed choice

    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. A25, 2208 (1982)

    1982

  18. [18]

    Y.-H. Kim, R. Yu, S. P. Kulik, Y. Shih, and M. O. Scully, Delayed “choice” quantum eraser, Phys. Rev. Lett.84, 1 (2000)

    2000

  19. [19]

    Jacques, E

    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- ence315, 966 (2007)

    2007

  20. [20]

    Tang, Y.-L

    J.-S. Tang, Y.-L. Li, X.-Y. Xu, G.-Y. Xiang, C.-F. Li, and G.-C. Guo, Realization of quantum Wheeler’s delayed- choice experiment, Nat. Photonics6, 600 (2012)

    2012

  21. [21]

    X.-s. Ma, S. Zotter, J. Kofler, R. Ursin, T. Jennewein, v. Brukner, and A. Zeilinger, Quantum erasure with causally disconnected choice, Proc. Natl. Acad. Sci.110, 1221 (2013)

    2013

  22. [22]

    S. K. Lee, N. S. Han, T. H. Yoon, and M. Cho, Frequency comb single-photon interferometry, Commun. Phys.1, 51 (2018)

    2018

  23. [23]

    T. Udem, R. Holzwarth, and T. W. H¨ ansch, Optical fre- quency metrology, Nature416, 233 (2002). 11

    2002

  24. [24]

    S. T. Cundiff and J. Ye, Colloquium: Femtosecond opti- cal frequency combs, Rev. Mod. Phys.75, 325 (2003)

    2003

  25. [25]

    M. Kues, C. Reimer, J. M. Lukens, W. J. Munro, A. M. Weiner, D. J. Moss, and R. Morandotti, Quantum optical microcombs, Nat. Photonics13, 170 (2019)

    2019

  26. [26]

    Reimer, L

    C. Reimer, L. Caspani, M. Clerici, M. Ferrera, M. Kues, M. Peccianti, A. Pasquazi, L. Razzari, B. E. Little, S. T. Chu, D. J. Moss, and R. Morandotti, Integrated fre- quency comb source of heralded single photons, Opt. Ex- press22, 6535 (2014)

    2014

  27. [27]

    Fujimoto, T

    R. Fujimoto, T. Yamazaki, T. Kobayashi, S. Miki, F. China, H. Terai, R. Ikuta, and T. Yamamoto, Entan- glement distribution using a biphoton frequency comb compatible with DWDM technology, Opt. Express30, 36711 (2022)

    2022

  28. [28]

    Yamazaki, R

    T. Yamazaki, R. Ikuta, T. Kobayashi, S. Miki, F. China, H. Terai, N. Imoto, and T. Yamamoto, Massive-mode po- larization entangled biphoton frequency comb, Sci. Rep. 12, 8964 (2022)

    2022

  29. [29]

    Zanardi and M

    P. Zanardi and M. Rasetti, Noiseless quantum codes, Phys. Rev. Lett.79, 3306 (1997)

    1997

  30. [30]

    D. A. Lidar, I. L. Chuang, and K. B. Whaley, Decoherence-free subspaces for quantum computation, Phys. Rev. Lett.81, 2594 (1998)

    1998

  31. [31]

    T. H. Yoon, A hardware-native time–frequency GKP logical qubit toward fault-tolerant photonic operation, arXiv:2602.14461 [quant-ph] 10.48550/arXiv.2602.14461 (2026)

    work page doi:10.48550/arxiv.2602.14461 2026