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A class of remote-controlled quantum computing models can be verified as nonclassical by violating dimension witnesses in the prepare-and-measure scenario.

2026-07-01 05:48 UTC pith:UTJBTOR6

load-bearing objection The paper maps modified RCQC models to a prepare-and-measure scenario and claims dimension-witness violations certify nonclassicality, but the reversed-order causal structure may invalidate the standard bounds without re-derivation. the 1 major comments →

arxiv 2606.31103 v1 pith:UTJBTOR6 submitted 2026-06-30 quant-ph

Nonclassicality of a delayed remote-controlled quantum computing model

Peicun Lin , Dongyang Wang , Yong Liu , Anqi Huang This is my paper
classification quant-ph
keywords remote-controlled quantum computingnonclassicalitydimension witnessesprepare-and-measure scenariosemi-device-independent verificationdelegated quantum computingquantum verification
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

The paper establishes that certain remote-controlled quantum computing models exhibit nonclassical behavior that clients can confirm without fully trusting the server hardware. With minor adjustments, these models map onto the prepare-and-measure scenario, where violations of dimension witnesses rule out any classical causal explanation. The same mapping reveals that the models process quantum information in reversed temporal order. An explicit check on a one-qubit unitary-measurement example confirms the violations occur. This supplies a semi-device-independent test for genuine quantum delegation.

Core claim

A class of remote-controlled quantum computing models presents nonclassical behavior that is verified in a semi-device-independent way. With slight modifications the models fit the prepare-and-measure scenario, so that violations of dimension witnesses rule out classical causal models. The same models exhibit reversed temporal order in quantum information processing. The nonclassicality is confirmed explicitly for a specific 1-U-M member of the class.

What carries the argument

Dimension witnesses applied to the prepare-and-measure scenario after mapping the RCQC models onto it, which tests whether observed correlations require more than classical dimension.

Load-bearing premise

Slight modifications let the RCQC models be faithfully described by the prepare-and-measure scenario without changing the computational task or the causal structure the witnesses are meant to test.

What would settle it

An experiment realizing the modified RCQC model in the prepare-and-measure scenario and recording a dimension-witness value no larger than the classical bound would falsify the nonclassicality claim.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • Clients gain a practical test to confirm that a delegated computation is genuinely quantum rather than classically simulable.
  • Classical causal models are excluded for the entire class once the dimension witnesses are violated.
  • The reversed temporal order appears as a direct consequence of the prepare-and-measure description of these models.
  • The explicit 1-U-M example demonstrates that the witness violation is observable with current quantum hardware.

Where Pith is reading between the lines

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

  • The same witness technique could be adapted to other delegated-computing protocols that share a prepare-and-measure structure.
  • Practical verification in quantum cloud services might become feasible if the required state preparations and measurements stay low-dimensional.
  • The reversed-order feature may connect to questions about causal order in broader quantum networks.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

1 major / 0 minor

Summary. The manuscript claims that a class of remote-controlled quantum computing (RCQC) models exhibits nonclassical behavior, which can be verified semi-device-independently by mapping the models (via slight modifications) to a prepare-and-measure scenario and demonstrating violations of dimension witnesses that rule out classical causal models. The work notes that this class exhibits reversed temporal order in quantum information processing and provides an explicit example verification for a specific 1-U-M RCQC model, aiming to connect fundamental quantum theory to practical delegated quantum computing verification.

Significance. If the mapping to the prepare-and-measure scenario is shown to preserve the relevant causal structure and the dimension-witness bounds are validated under the reversed temporal order, the result would provide a concrete semi-device-independent method for certifying nonclassicality in remote quantum computing tasks, strengthening the link between dimension-witness techniques and applied verification protocols.

major comments (1)
  1. [Abstract (mapping and witness application); main text sections describing the RCQC-to-prepare-and-measure reduction and ] The central mapping claim (abstract): the abstract states that 'with slight modifications, these models can be described by the prepare-and-measure scenario' and that 'violations of dimension witnesses' rule out classical causal models. However, the paper highlights 'reversed temporal order in quantum information processing' for this class. Standard dimension witnesses in prepare-and-measure scenarios are derived under the assumption that the preparer's output precedes the measurer's input in the causal partial order. The manuscript must explicitly show (e.g., via re-derivation or invariance proof) that the witness inequalities remain valid under the reversed-order causal structure after the modifications; otherwise the numerical violations do not necessarily exclude classical models compatible with the actual causal diagram of the RCQC task.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful review and for identifying the need to rigorously justify the applicability of dimension witnesses under the reversed temporal order. We address the concern below.

read point-by-point responses

  1. Referee: The central mapping claim (abstract): the abstract states that 'with slight modifications, these models can be described by the prepare-and-measure scenario' and that 'violations of dimension witnesses' rule out classical causal models. However, the paper highlights 'reversed temporal order in quantum information processing' for this class. Standard dimension witnesses in prepare-and-measure scenarios are derived under the assumption that the preparer's output precedes the measurer's input in the causal partial order. The manuscript must explicitly show (e.g., via re-derivation or invariance proof) that the witness inequalities remain valid under the reversed-order causal structure after the modifications; otherwise the numerical violations do not necessarily exclude classical models compatible with the actual causal diagram of the RCQC task.

    Authors: We agree that an explicit demonstration is required. The slight modifications map the RCQC models to a prepare-and-measure scenario while preserving the relevant no-signaling constraints that underlie the dimension-witness bounds. In the revised manuscript we will add a dedicated subsection that re-derives the witness inequalities from the modified causal structure, confirming that the bounds remain unchanged and that violations continue to exclude classical models compatible with the RCQC diagram. revision: yes

Circularity Check

0 steps flagged

No circularity: derivation relies on standard dimension witnesses after explicit mapping

full rationale

The paper's core step maps RCQC models to the prepare-and-measure scenario via stated modifications, then invokes violations of dimension witnesses to rule out classical causal models. This follows the established prepare-and-measure certification framework without reducing any claimed prediction to a fitted parameter, self-definition, or self-citation chain. No equations in the provided abstract or description equate the witness bound to the RCQC input by construction, and the reversed temporal order is presented as an observed feature rather than an ansatz smuggled in. The argument is therefore self-contained against external benchmarks in quantum information theory.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract-only review supplies no explicit free parameters, axioms, or invented entities. The central claim rests on the unstated assumption that the RCQC-to-prepare-and-measure mapping is faithful and that dimension witnesses apply without additional calibration.

pith-pipeline@v0.9.1-grok · 5709 in / 1132 out tokens · 13975 ms · 2026-07-01T05:48:36.064274+00:00 · methodology

0 comments
read the original abstract

Delegated quantum computing is likely to become the primary means for most people to access quantum computers in the future. However, these hardware inevitably operate beyond clients' control, raising concerns about potentially untrusted servers. A fundamental question thus arises -- how can clients verify that the server is genuinely performing quantum computations? Here, we demonstrate that a class of remote-controlled quantum computing (RCQC) models presents the nonclassical behavior verified in a semi-device-independent way. To achieve this, with slight modifications, these models can be described by the prepare-and-measure scenario. By verifying the violations of dimension witnesses, classical causal models can be ruled out, thereby showing nonclassicality of the RCQC model. Remarkably, in the prepare-and-measure scenario, this class of RCQC models happens to exhibit reversed temporal order in quantum information processing. We also explicitly confirm the nonclassical behaviors of a specific 1-U-M RCQC model belonging to this class as an example. This work bridges the fundamental quantum theory with the practical task of quantum computing.

Figures

Figures reproduced from arXiv: 2606.31103 by Anqi Huang, Dongyang Wang, Peicun Lin, Yong Liu.

Figure 1
Figure 1. Figure 1: FIG. 1. The scheme of remote-controlled quantum comput [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Possible causal structures of the PAM scenario. Clas [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. A specific implementation of the delayed 1-U-M [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Visualizations of the value of the dimension witnesses. (a) The visualization of the possible maximum values of det( [PITH_FULL_IMAGE:figures/full_fig_p006_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5. The prepare-and-measure (PAM) scenario rep [PITH_FULL_IMAGE:figures/full_fig_p007_5.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

41 extracted references · 41 canonical work pages · 1 internal anchor

  1. [1]

    P. W. Shor, Polynomial-time algorithms for prime factor- ization and discrete logarithms on a quantum computer, SIAM J. Comput.41, 303 (1995)

    work page 1995

  2. [2]

    L. K. Grover, Quantum mechanics helps in searching for a needle in a haystack, Phys. Rev. Lett.79, 325 (1997)

    work page 1997

  3. [3]

    Biamonte, P

    J. Biamonte, P. Wittek, N. Pancotti, P. Rebentrost, N. Wiebe, and S. Lloyd, Quantum machine learning, Na- ture549(2017)

    work page 2017

  4. [4]

    … … 0, , 1x N= … − 0, , 1y M= … − r λ FIG

    (n.d.), center for Quantum Photonics, Quantum in the Cloud,https://cnotmz.appspot.com/. … … 0, , 1x N= … − 0, , 1y M= … − r λ FIG. 5. The prepare-and-measure (PAM) scenario rep- resented by black boxes. Upon pressing a buttonx∈ {0,1, . . . , N−1}, the preparator sends a physical systemλ to the measurement device. When receive the physical sys- temλand pre...

    work page

  5. [5]

    Steffen, J

    M. Steffen, J. M. Gambetta, and J. M. Chow, Progress, status, and prospects of superconducting qubits for quan- tum computing, in2016 46th European Solid-State De- vice Research Conference (ESSDERC)(2016) pp. 17–20

    work page 2016

  6. [6]

    Alsina and J

    D. Alsina and J. I. Latorre, Experimental test of mer- min inequalities on a five-qubit quantum computer, Phys. Rev. A94, 012314 (2016)

    work page 2016

  7. [7]

    S. J. Devitt, Performing quantum computing experi- ments in the cloud, Phys. Rev. A94, 032329 (2016)

    work page 2016

  8. [8]

    Hebenstreit, D

    M. Hebenstreit, D. Alsina, J. I. Latorre, and B. Kraus, Compressed quantum computation using a remote five- qubit quantum computer, Phys. Rev. A95, 052339 (2017)

    work page 2017

  9. [9]

    Y. Wang, Y. Li, Z. Yin, and B. Zeng, 16-qubit ibm univer- sal quantum computer can be fully entangled, npj Quan- tum Inf.4(2018)

    work page 2018

  10. [10]

    H. T. Nguyen, P. Krishnan, D. Krishnaswamy, M. Us- man, and R. Buyya, Quantum cloud computing: A review, open problems, and future directions (2024), arXiv:2404.11420 [cs.ET]

    work page Pith review arXiv 2024

  11. [11]

    Broadbent, J

    A. Broadbent, J. Fitzsimons, and E. Kashefi, Universal blind quantum computation, in2009 50th Annual IEEE Symposium on Foundations of Computer Science(2009) pp. 517–526

    work page 2009

  12. [12]

    Aharonov, M

    D. Aharonov, M. Ben-Or, and E. Eban, Interactive proofs for quantum computations, inInnovations in Computer Science - ICS 2010(2010) pp. 453–469

    work page 2010

  13. [13]

    B. W. Reichardt, F. Unger, and U. Vazirani, A classical leash for a quantum system: Command of quantum sys- tems via rigidity of chsh games (2012), arXiv:1209.0448 [quant-ph]

    work page internal anchor Pith review Pith/arXiv arXiv 2012

  14. [14]

    Morimae and K

    T. Morimae and K. Fujii, Blind quantum computation protocol in which alice only makes measurements, Phys. Rev. A87, 050301 (2013)

    work page 2013

  15. [15]

    B. W. Reichardt, F. Unger, and U. Vazirani, Classical command of quantum systems, Nature496, 456 (2013)

    work page 2013

  16. [16]

    Hayashi and T

    M. Hayashi and T. Morimae, Verifiable measurement- only blind quantum computing with stabilizer testing, Phys. Rev. Lett.115, 220502 (2015)

    work page 2015

  17. [17]

    Broadbent, How to verify a quantum computation, Theory Comput.14, 1 (2018)

    A. Broadbent, How to verify a quantum computation, Theory Comput.14, 1 (2018)

    work page 2018

  18. [18]

    J. F. Fitzsimons, M. Hajduˇ sek, and T. Morimae, Post hoc verification of quantum computation, Phys. Rev. Lett. 120, 040501 (2018). 8

    work page 2018

  19. [19]

    Broadbent and S

    A. Broadbent and S. Jeffery, Quantum homomorphic en- cryption for circuits of low t-gate complexity, inAdvances in Cryptology – CRYPTO 2015(2015) pp. 609–629

    work page 2015

  20. [20]

    Dulek, C

    Y. Dulek, C. Schaffner, and F. Speelman, Quantum ho- momorphic encryption for polynomial-sized circuits, in Advances in Cryptology – CRYPTO 2016(2016) pp. 3– 32

    work page 2016

  21. [21]

    Q. Li, Y. Wang, L. Chen, and L. Li, Verifiable quantum homomorphic encryption, IEEE J. Sel. Areas Commun. 43, 2898 (2025)

    work page 2025

  22. [22]

    Qiang, X

    X. Qiang, X. Zhou, K. Aungskunsiri, H. Cable, and J. L. O’Brien, Quantum processing by remote quantum con- trol, Quantum Sci. Technol.2, 045002 (2017)

    work page 2017

  23. [23]

    D. Wang, Y. Liu, J. Ding, X. Qiang, Y. Liu, A. Huang, X. Fu, P. Xu, M. Deng, X. Yang, and J. Wu, Remote- controlled quantum computing by quantum entangle- ment, Opt. Lett.45, 6298 (2020)

    work page 2020

  24. [24]

    past” and the “delayed-choice

    J. A. Wheeler, The “past” and the “delayed-choice” double-slit experiment, inMathematical Foundations of Quantum Theory, edited by A. R. Marlow (Academic Press, 1978) pp. 9–48

    work page 1978

  25. [25]

    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, Science 315, 966 (2007)

    work page 2007

  26. [26]

    Ionicioiu and D

    R. Ionicioiu and D. R. Terno, Proposal for a quantum delayed-choice experiment, Phys. Rev. Lett.107, 230406 (2011)

    work page 2011

  27. [27]

    Kaiser, T

    F. Kaiser, T. Coudreau, P. Milman, D. B. Ostrowsky, and S. Tanzilli, Entanglement-enabled delayed-choice experi- ment, Science338, 637 (2012)

    work page 2012

  28. [28]

    Ionicioiu, T

    R. Ionicioiu, T. Jennewein, R. B. Mann, and D. R. Terno, Is wave-particle objectivity compatible with determinism and locality?, Nat. Commun.5, 1 (2014)

    work page 2014

  29. [29]

    K. Wang, Q. Xu, S. Zhu, and X. s. Ma, Quantum wave–particle superposition in a delayed-choice experi- ment, Nat. Photonics13, 1 (2019)

    work page 2019

  30. [30]

    Pearl,Causality: Models, Reasoning and Inference, 2nd ed

    J. Pearl,Causality: Models, Reasoning and Inference, 2nd ed. (Cambridge University Press, USA, 2009)

    work page 2009

  31. [31]

    Chaves, G

    R. Chaves, G. B. Lemos, and J. Pienaar, Causal model- ing the delayed-choice experiment, Phys. Rev. Lett.120, 190401 (2018)

    work page 2018

  32. [32]

    Bowles, M

    J. Bowles, M. T. Quintino, and N. Brunner, Certify- ing the dimension of classical and quantum systems in a prepare-and-measure scenario with independent devices, Phys. Rev. Lett.112, 140407 (2014)

    work page 2014

  33. [33]

    Gallego, N

    R. Gallego, N. Brunner, C. Hadley, and A. Ac´ ın, Device- independent tests of classical and quantum dimensions, Phys. Rev. Lett.105, 230501 (2010)

    work page 2010

  34. [34]

    Polino, I

    E. Polino, I. Agresti, D. Poderini, G. Carvacho, G. Mi- lani, G. B. Lemos, R. Chaves, and F. Sciarrino, Device- independent test of a delayed choice experiment, Phys. Rev. A100, 022111 (2019)

    work page 2019

  35. [35]

    Yu, Y.-N

    S. Yu, Y.-N. Sun, W. Liu, Z.-D. Liu, Z.-J. Ke, Y.-T. Wang, J.-S. Tang, C.-F. Li, and G.-C. Guo, Realization of a causal-modeled delayed-choice experiment using single photons, Phys. Rev. A100, 012115 (2019)

    work page 2019

  36. [36]

    Huang, Y.-H

    H.-L. Huang, Y.-H. Luo, B. Bai, Y.-H. Deng, H. Wang, Q. Zhao, H.-S. Zhong, Y.-Q. Nie, W.-H. Jiang, X.-L. Wang, J. Zhang, L. Li, N.-L. Liu, T. Byrnes, J. P. Dowl- ing, C.-Y. Lu, and J.-W. Pan, Compatibility of causal hidden-variable theories with a delayed-choice experi- ment, Phys. Rev. A100, 012114 (2019)

    work page 2019

  37. [37]

    M. A. Nielsen and I. L. Chuang, Programmable quantum gate arrays, Phys. Rev. Lett.79, 321 (1997)

    work page 1997

  38. [38]

    Gschwendtner and A

    M. Gschwendtner and A. Winter, Infinite-dimensional programmable quantum processors, PRX Quantum2, 030308 (2021)

    work page 2021

  39. [39]

    de Gois, G

    C. de Gois, G. Moreno, R. Nery, S. Brito, R. Chaves, and R. Rabelo, General method for classicality certification in the prepare and measure scenario, PRX Quantum2, 030311 (2021)

    work page 2021

  40. [40]

    Poderini, S

    D. Poderini, S. Brito, R. Nery, F. Sciarrino, and R. Chaves, Criteria for nonclassicality in the prepare-and- measure scenario, Phys. Rev. Res.2, 043106 (2020)

    work page 2020

  41. [41]

    Reference [?] proposes a method to block communica- tion between devices

    work page