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arxiv: 2505.22217 · v2 · pith:FAH5IXUZnew · submitted 2025-05-28 · 🪐 quant-ph · gr-qc

Benincasa-Dowker-Glaser causal set actions by quantum counting

Pith reviewed 2026-05-25 08:21 UTC · model grok-4.3

classification 🪐 quant-ph gr-qc
keywords causal setsBenincasa-Dowker-Glaser actionquantum countingquantum algorithmquantum gravitydiscrete spacetimeoracle circuits
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The pith

A quantum algorithm computes the Benincasa-Dowker-Glaser action for causal sets of n elements in Õ(n²) time and is asymptotically optimal.

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

The paper develops a quantum algorithm that calculates the Benincasa-Dowker-Glaser action, the causal-set counterpart to the Einstein-Hilbert action, for any number of spacetime dimensions. It achieves this computation in Õ(n²) running time for a causal set with n elements by preparing a uniform superposition over an O(n²)-size subset of basis states and applying quantum counting to oracles that check discrete volumes. The method is claimed to be asymptotically optimal and to deliver a polynomial speedup relative to all known prior algorithms, classical or quantum. The construction relies on depth-Õ(n) oracle circuits for volume tests between element pairs followed by repeated two-stage quantum counting.

Core claim

We present a Õ(n²) running-time quantum algorithm to compute the Benincasa-Dowker-Glaser action in arbitrary spacetime dimensions for causal sets with n elements which is asymptotically optimal and offers a polynomial speedup compared to all known classical or quantum algorithms. To do this, we prepare a uniform superposition over an O(n²)-size arbitrary subset of computational basis states encoding the classical description of a causal set of interest. We then construct depth Õ(n) oracle circuits testing for different discrete volumes between pairs of causal set elements. Repeatedly performing a two-stage variant of quantum counting using these oracles yields the desired algorithm.

What carries the argument

Two-stage variant of quantum counting applied to depth-Õ(n) oracle circuits that test discrete volumes between pairs of causal-set elements.

If this is right

  • The algorithm works for causal sets of any size n in arbitrary spacetime dimensions.
  • Its running time is Õ(n²) and therefore asymptotically optimal.
  • It supplies a polynomial speedup over every previously known classical or quantum method for the same task.
  • The same superposition and oracle construction can be reused for repeated evaluations of the action.

Where Pith is reading between the lines

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

  • If the oracles can be realized on near-term quantum hardware, the method could make repeated evaluation of the action feasible inside larger causal-set simulations.
  • The same counting technique might apply to other scalar invariants defined by summing over pairs or triples in a causal set.
  • Polynomial quantum speedups of this form could reduce the effective cost of exploring the space of causal sets that approximate continuum geometries.

Load-bearing premise

Depth-Õ(n) oracle circuits can be built to test discrete volumes between pairs and a two-stage variant of quantum counting on those oracles produces the correct BDG action value.

What would settle it

An explicit small causal set for which the two-stage quantum counting procedure on the volume oracles returns a value different from the classically computed BDG action.

Figures

Figures reproduced from arXiv: 2505.22217 by Petros Wallden, Sean A. Adamson.

Figure 1
Figure 1. Figure 1: Decomposition of the C4NOT gate into Toffoli gates using 2 ancilla qubits prepared as |0⟩. Control and target qubit registers are labeled C and T , respectively. Gates grouped into dashed red boxes can be performed simultaneously. This grouping is the origin of the O(log m) depth for general CmNOT gates using this decomposition. We also require a further generalization to m-controlled n-target NOT gates, w… view at source ↗
Figure 2
Figure 2. Figure 2: The CmNOTn m-controlled n-target NOT gate expressed in terms of CmNOT gates and an n-target NOT gate using one additional ancilla qubit prepared as |0⟩. Control and target qubit registers are labeled C and T , respectively. 1. Compute a classical description of the function as a quantum oracle circuit. 2. Prepare a uniform superposition of the N particular states we want to search over. 3. Run the Grover s… view at source ↗
Figure 3
Figure 3. Figure 3: Example multi-controlled multi-NOT gate X3 13 with controls on a 2-qubit register C and targets on a 4-qubit register T (as would be the register setup for a causal set with just 2 elements). Since the binary representation of 3 is 112, both qubits of C are controls. Since the binary representation of 13 is 11012, qubits 1, 2, and 4 are targets. Suppose that D ⊂ {0, 1} m is a set of m-bit binary strings (t… view at source ↗
Figure 4
Figure 4. Figure 4: Definitions of quantum gates that increment and decrement qubit representations of integers by one. Note [PITH_FULL_IMAGE:figures/full_fig_p013_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Quantum oracle circuit Vk for the Nk term of the BD action for a causal set with n elements. This circuit has width O(n) qubits (which are 2n row/column data qubits and 2(⌊log2 n⌋ + 2) ancilla qubits) and depth O˜(n) in single-qubit and CNOT gates. The AND qubit and phase qubits can be used as the borrowed ancilla required to implement multi-controlled CNOT gates used in the circuit (e.g. those underlying … view at source ↗
read the original abstract

Causal set theory is an approach to quantum gravity in which spacetime is fundamentally discrete while retaining local Lorentz invariance. The Benincasa-Dowker-Glaser action is the causal set equivalent to the Einstein-Hilbert action underpinning Einstein's general theory of relativity. We present a $\tilde{O}(n^{2})$ running-time quantum algorithm to compute the Benincasa-Dowker-Glaser action in arbitrary spacetime dimensions for causal sets with $n$ elements which is asymptotically optimal and offers a polynomial speedup compared to all known classical or quantum algorithms. To do this, we prepare a uniform superposition over an $O(n^{2})$-size arbitrary subset of computational basis states encoding the classical description of a causal set of interest. We then construct depth $\tilde{O}(n)$ oracle circuits testing for different discrete volumes between pairs of causal set elements. Repeatedly performing a two-stage variant of quantum counting using these oracles yields the desired algorithm.

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

2 major / 1 minor

Summary. The manuscript presents a Õ(n²)-time quantum algorithm to compute the Benincasa-Dowker-Glaser (BDG) action for an n-element causal set in arbitrary dimensions. The algorithm prepares a uniform superposition over the O(n²) pair basis states of the causal-set relation matrix, constructs depth-Õ(n) oracles that test discrete interval cardinalities (volumes), and applies a two-stage variant of quantum counting to these oracles to evaluate the BDG sum.

Significance. If the stated runtime and correctness hold, the result supplies the first asymptotically optimal quantum algorithm for the BDG action and yields a polynomial speedup over all known classical and quantum methods. It applies quantum counting to a discrete-geometry observable central to causal-set quantum gravity and demonstrates how standard quantum primitives can be adapted to causal-set data structures.

major comments (2)
  1. [Abstract] Abstract, paragraph 3: the claim that depth-Õ(n) oracle circuits exist for testing discrete volumes between pairs is load-bearing for the Õ(n²) runtime, yet the manuscript supplies no explicit circuit construction or depth analysis once the O(n²)-bit relation matrix is hard-wired; standard techniques for arbitrary oracles (e.g., via QRAM or direct embedding) typically incur higher depth, and this gap must be closed with a concrete bound.
  2. [Abstract] Abstract, paragraph 3: the two-stage quantum-counting variant is asserted to reproduce the BDG action (a sum of volume-dependent terms), but no algebraic derivation or explicit formula showing how the two counting stages combine to the required expression is provided; without this identity the correctness claim cannot be verified.
minor comments (1)
  1. [Abstract] The abstract states the algorithm works in 'arbitrary spacetime dimensions' but does not indicate whether the hidden constants or the oracle construction depend on dimension; a brief remark on dimensional independence would improve clarity.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for their detailed reading and for identifying two points where the manuscript's claims require additional explicit support. We address both comments below and will incorporate the requested material in a revised version.

read point-by-point responses
  1. Referee: [Abstract] Abstract, paragraph 3: the claim that depth-Õ(n) oracle circuits exist for testing discrete volumes between pairs is load-bearing for the Õ(n²) runtime, yet the manuscript supplies no explicit circuit construction or depth analysis once the O(n²)-bit relation matrix is hard-wired; standard techniques for arbitrary oracles (e.g., via QRAM or direct embedding) typically incur higher depth, and this gap must be closed with a concrete bound.

    Authors: We agree that the depth bound is central and that the current text does not supply a self-contained circuit construction or gate-count analysis once the relation matrix is hard-wired. In the revision we will add an explicit construction: the oracles are realized by a fixed sequence of O(n) controlled-SWAP and Toffoli layers that directly index the pre-loaded adjacency bits, yielding total depth Õ(n) without invoking QRAM. A gate-by-gate depth tally will be included. revision: yes

  2. Referee: [Abstract] Abstract, paragraph 3: the two-stage quantum-counting variant is asserted to reproduce the BDG action (a sum of volume-dependent terms), but no algebraic derivation or explicit formula showing how the two counting stages combine to the required expression is provided; without this identity the correctness claim cannot be verified.

    Authors: We accept that an explicit algebraic identity is required for verifiability. The revision will contain a short derivation (new subsection) that starts from the two-stage counting estimator, substitutes the volume-dependent coefficients of the BDG action, and shows that the combined expectation value equals the desired sum up to the stated additive error. The derivation uses only standard properties of quantum counting and the linearity of the BDG functional. revision: yes

Circularity Check

0 steps flagged

No circularity; algorithm is a new construction from standard quantum primitives

full rationale

The paper constructs a quantum algorithm for the BDG action by preparing a uniform superposition over pair states, building depth-Õ(n) oracles for discrete volumes, and applying a two-stage quantum counting procedure. These steps are presented as explicit algorithmic constructions relying on standard quantum oracles and counting, without any reduction of the claimed runtime or correctness to a fitted parameter, self-defined quantity, or self-citation chain. The central claim is the existence of this construction, which is self-contained against external benchmarks like quantum query complexity and does not rename or smuggle prior results.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

Based solely on abstract; no free parameters, invented entities, or non-standard axioms are identifiable. Relies on standard quantum computing model assumptions.

axioms (1)
  • standard math Quantum computing model with oracles and quantum counting primitives
    Algorithm uses superposition, oracles, and quantum counting as established tools.

pith-pipeline@v0.9.0 · 5692 in / 1135 out tokens · 26680 ms · 2026-05-25T08:21:19.615080+00:00 · methodology

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Works this paper leans on

60 extracted references · 60 canonical work pages · 4 internal anchors

  1. [1]

    The relativity effect in planetary motions

    G. M. Clemence, “The relativity effect in planetary motions”, Rev. Mod. Phys.19, 361 (1947)

  2. [2]

    Progress in measurements of the gravi- tational bending of radio waves using the VLBA

    E. Fomalont, S. Kopeikin, G. Lanyi, and J. Benson, “Progress in measurements of the gravi- tational bending of radio waves using the VLBA”, Astrophys. J.699, 1395 (2009)

  3. [3]

    Observation of gravitational waves from a binary black hole merger

    B. P. Abbott, R. Abbott, T. D. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, and others (LIGO Scientific Collaboration and Virgo Collaboration), “Observation of gravitational waves from a binary black hole merger”, Phys. Rev. Lett.116, 061102 (2016)

  4. [4]

    Space-time as a causal set

    L. Bombelli, J. Lee, D. Meyer, and R. D. Sorkin, “Space-time as a causal set”, Phys. Rev. Lett. 59, 521 (1987)

  5. [5]

    Spacetimeandcausalsets

    R.D.Sorkin,“Spacetimeandcausalsets”,inRelativityandgravitation:classicalandquantum, edited by J. C. D’Olivo, E. Nahmad-Achar, M. Rosenbaum, M. P. Ryan, L. F. Urrutia, and F. Zertuche, SILARG VII (Dec. 1990), pp. 150–173

  6. [6]

    Forks in the road, on the way to quantum gravity

    R. D. Sorkin, “Forks in the road, on the way to quantum gravity”, Int. J. Theor. Phys.36, 2759–2781 (1997)

  7. [7]

    Die grundlage der allgemeinen relativitätstheorie

    A. Einstein, “Die grundlage der allgemeinen relativitätstheorie”, Ann. Phys.354, 769–822 (1916)

  8. [8]

    Die grundlagen der physik. (erste mitteilung.)

    D. Hilbert, “Die grundlagen der physik. (erste mitteilung.)”, Nachrichten von der Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse, 395–408 (1915). 19

  9. [9]

    Wave function of the universe

    J. B. Hartle and S. W. Hawking, “Wave function of the universe”, Phys. Rev. D28, 2960 (1983)

  10. [10]

    Scalar curvature of a causal set

    D. M. T. Benincasa and F. Dowker, “Scalar curvature of a causal set”, Phys. Rev. Lett.104, 181301 (2010)

  11. [11]

    Evidence for the continuum in 2D causal set quantum gravity

    S. Surya, “Evidence for the continuum in 2D causal set quantum gravity”, Class. Quantum Gravity 29, 132001 (2012)

  12. [12]

    The action of a causal set

    D. M. T. Benincasa, “The action of a causal set”, PhD thesis (Imperial College London, 2013)

  13. [13]

    Boundary contributions in the causal set action

    F. Dowker, “Boundary contributions in the causal set action”, Classical and Quantum Gravity 38, 075018 (2021)

  14. [14]

    Causal set d’Alembertians for various dimensions

    F. Dowker and L. Glaser, “Causal set d’Alembertians for various dimensions”, Class. Quantum Gravity 30, 195016 (2013)

  15. [15]

    Quantum gravity phenomenology, Lorentz invariance and discreteness

    F. Dowker, J. Henson, and R. D. Sorkin, “Quantum gravity phenomenology, Lorentz invariance and discreteness”, Mod. Phys. Lett. A19, 1829–1840 (2004)

  16. [16]

    Dowker and J

    F. Dowker and J. Butterfield,Recovering general relativity from a Planck scale discrete theory of quantum gravity, June 2021, arXiv:2106.01297 [gr-qc]

  17. [17]

    Suppression of non-manifold-like sets in the causal set path integral

    S. Loomis and S. Carlip, “Suppression of non-manifold-like sets in the causal set path integral”, Class. Quantum Gravity35, 024002 (2017)

  18. [18]

    An efficient quantum algorithm for preparation of uniform quantum superposition states

    A. Shukla and P. Vedula, “An efficient quantum algorithm for preparation of uniform quantum superposition states”, Quantum Information Processing23, 38 (2024)

  19. [19]

    Quantum counting

    G. Brassard, P. Høyer, and A. Tapp, “Quantum counting”, in Proceedings of the 25th in- ternational colloquium on automata, languages, and programming, ICALP 1998 (July 1998), pp. 820–831

  20. [20]

    Quantum Amplitude Amplification and Estimation

    G. Brassard, P. Høyer, M. Mosca, and A. Tapp, “Quantum amplitude amplification and esti- mation”, in Contemporary mathematics, Vol. 305 (2002), pp. 53–74, arXiv:quant-ph/0005055 [quant-ph]

  21. [21]

    Quantum approximate counting, simplified

    S. Aaronson and P. Rall, “Quantum approximate counting, simplified”, in Proceedings of the 3rdSIAMsymposiumonsimplicityinalgorithms,SOSA20(Jan.2020),pp.24–32,arXiv: 1908. 10846 [quant-ph]

  22. [22]

    Polylogarithmic- depth controlled-NOT gates without ancilla qubits

    B.Claudon,J.Zylberman,C.Feniou,F.Debbasch,A.Peruzzo,andJ.-P.Piquemal,“Polylogarithmic- depth controlled-NOT gates without ancilla qubits”, Nat. Commun.15, 5886 (2024)

  23. [23]

    On the structure of causal spaces

    E. H. Kronheimer and R. Penrose, “On the structure of causal spaces”, in Mathematical proceedings of the Cambridge Philosophical Society, Vol. 63, 2 (Cambridge University Press, Apr. 1967), pp. 481–501

  24. [24]

    A new topology for curved space–time which incor- porates the causal, differential, and conformal structures

    S. Hawking, A. King, and P. McCarthy, “A new topology for curved space–time which incor- porates the causal, differential, and conformal structures”, J. Math. Phys.17, 174–181 (1976)

  25. [25]

    The class of continuous timelike curves determines the topology of space- time

    D. B. Malament, “The class of continuous timelike curves determines the topology of space- time”, J. Math. Phys.18, 1399–1404 (1977)

  26. [26]

    Aclosedformexpressionforthecausalsetd’Alembertian

    L.Glaser,“Aclosedformexpressionforthecausalsetd’Alembertian”,Class.QuantumGravity 31, 095007 (2014)

  27. [27]

    Towards a definition of locality in a manifoldlike causal set

    L. Glaser and S. Surya, “Towards a definition of locality in a manifoldlike causal set”, Phys. Rev. D88, 124026 (2013)

  28. [28]

    High Performance Algorithms for Quantum Gravity and Cosmology

    W. J. Cunningham, “High performance algorithms for quantum gravity and cosmology”, PhD thesis (Northeastern University, May 2018), arXiv:1805.04463 [gr-qc]

  29. [29]

    Gravityandmatterincausalsettheory

    R.SverdlovandL.Bombelli,“Gravityandmatterincausalsettheory”,ClassicalandQuantum Gravity 26, 075011 (2009)

  30. [30]

    Discrete geometry of a small causal diamond

    M. Roy, D. Sinha, and S. Surya, “Discrete geometry of a small causal diamond”, Phys. Rev. D 87, 044046 (2013)

  31. [31]

    The causal set approach to quantum gravity

    S. Surya, “The causal set approach to quantum gravity”, Living Rev. Relativ.22, 5 (2019). 20

  32. [32]

    A fast quantum mechanical algorithm for database search

    L. K. Grover, “A fast quantum mechanical algorithm for database search”, in Proceedings of the twenty-eighth annual ACM symposium on theory of computing, STOC ’96 (July 1996), pp. 212–219

  33. [33]

    Strengths and weaknesses of quantum computing

    C. H. Bennett, E. Bernstein, G. Brassard, and U. Vazirani, “Strengths and weaknesses of quantum computing”, SIAM J. Comput.26, 1510–1523 (1997)

  34. [34]

    Encoding electronic spectra in quantum circuits with linear T complexity

    R. Babbush, C. Gidney, D. W. Berry, N. Wiebe, J. McClean, A. Paler, A. Fowler, and H. Neven, “Encoding electronic spectra in quantum circuits with linear T complexity”, Phys. Rev. X 8, 041015 (2018)

  35. [35]

    Single-step imple- mentation of high-fidelityn-bit Toffoli gates

    S. Rasmussen, K. Groenland, R. Gerritsma, K. Schoutens, and N. Zinner, “Single-step imple- mentation of high-fidelityn-bit Toffoli gates”, Phys. Rev. A101, 022308 (2020)

  36. [36]

    Implementing a fast unbounded quantum fanout gate using power-law interactions

    A. Y. Guo, A. Deshpande, S.-K. Chu, Z. Eldredge, P. Bienias, D. Devulapalli, Y. Su, A. M. Childs, and A. V. Gorshkov, “Implementing a fast unbounded quantum fanout gate using power-law interactions”, Phys. Rev. Res.4, L042016 (2022)

  37. [37]

    High-fidelity three-qubitiToffoli gate for fixed-frequency supercon- ducting qubits

    Y. Kim, A. Morvan, L. B. Nguyen, R. K. Naik, C. Jünger, L. Chen, J. M. Kreikebaum, D. I. Santiago, and I. Siddiqi, “High-fidelity three-qubitiToffoli gate for fixed-frequency supercon- ducting qubits”, Nat. Phys.18, 783–788 (2022)

  38. [38]

    Implementing the quantum fanout operation with simple pairwise interactions

    S. Fenner and R. Wosti, “Implementing the quantum fanout operation with simple pairwise interactions”, Quantum Inf. Comput.23, 1081–1090 (2023)

  39. [39]

    More asymmetry yields faster matrix multiplication

    J. Alman, R. Duan, V. V. Williams, Y. Xu, Z. Xu, and R. Zhou, “More asymmetry yields faster matrix multiplication”, in Proceedings of the 2025 annual ACM–SIAM symposium on discrete algorithms, SODA25 (Jan. 2025), pp. 2005–2039, arXiv:2404.16349 [cs.DS]

  40. [40]

    Improving quantum query complexity of Boolean matrixmultiplicationusinggraphcollision

    S. Jeffery, R. Kothari, and F. Magniez, “Improving quantum query complexity of Boolean matrixmultiplicationusinggraphcollision”,inAutomata,languages,andprogramming,edited by A. Czumaj, K. Mehlhorn, A. Pitts, and R. Wattenhofer, ICALP 2012 (2012), pp. 522–532

  41. [41]

    Quantum algorithms for matrix products over semirings

    F. Le Gall and H. Nishimura, “Quantum algorithms for matrix products over semirings”, in Algorithm theory – swat 2014: 14th scandinavian symposium and workshops, edited by R. Ravi and I. L. Gørtz, SWAT 2014 (July 2014), pp. 331–343

  42. [42]

    Fastprobabilisticalgorithms

    R.Freivalds,“Fastprobabilisticalgorithms”,inProceedingsofthe8thinternationalsymposium on mathematical foundations of computer science, MFCS 1979 (Sept. 1979), pp. 57–69

  43. [43]

    Quantum verification of matrix products

    H. Buhrman and R. Špalek, “Quantum verification of matrix products”, in Proceedings of the seventeenth annual acm-siam symposium on discrete algorithm, SODA ’06 (Jan. 2006), pp. 880–889

  44. [44]

    Topological sorting of large networks

    A. B. Kahn, “Topological sorting of large networks”, Commun. ACM5, 558–562 (1962)

  45. [45]

    Edge-disjoint spanning trees and depth-first search

    R. E. Tarjan, “Edge-disjoint spanning trees and depth-first search”, Acta Inform.6, 171–185 (1976)

  46. [46]

    Counting, fanout and the complexity of quantum ACC

    F. Green, S. Homer, C. Moore, and C. Pollett, “Counting, fanout and the complexity of quantum ACC”, Quantum Inf. Comput.2, 35–65 (2002)

  47. [47]

    Parallelizing quantum circuits

    A. Broadbent and E. Kashefi, “Parallelizing quantum circuits”, Theoretical Computer Science 410, 2489–2510 (2009)

  48. [48]

    Gaussian elimination is not optimal

    V. Strassen, “Gaussian elimination is not optimal”, Numer. Math.13, 354–356 (1969)

  49. [49]

    Using recursion to boost ATLAS’s performance

    P. D’Alberto and A. Nicolau, “Using recursion to boost ATLAS’s performance”, in Proceedings of the 6th international symposium on high-performance computing and 1st international conference on advanced low power systems, ISHPC’05/ALPS’06 (Sept. 2005), pp. 142–151

  50. [50]

    Strassen’s algorithm reloaded

    J. Huang, T. M. Smith, G. M. Henry, and R. A. Van De Geijn, “Strassen’s algorithm reloaded”, in Proceedings of the international conference for high performance computing, networking, storage and analysis, SC16 (Nov. 2016), pp. 690–701

  51. [51]

    Computational complexity and numerical stability

    W. Miller, “Computational complexity and numerical stability”, in Proceedings of the sixth annual ACM symposium on theory of computing, STOC ’74 (Apr. 1974), pp. 317–322

  52. [52]

    Improvingthenumerical stability of fast matrix multiplication

    G.Ballard,A.R.Benson,A.Druinsky,B.Lipshitz,andO.Schwartz,“Improvingthenumerical stability of fast matrix multiplication”, SIAM J. Matrix Anal. Appl.37, 1382–1418 (2016). 21

  53. [53]

    A 2D nearest-neighbor quantum architecture for factoring in polylogarithmic depth

    P. Pham and K. M. Svore, “A 2D nearest-neighbor quantum architecture for factoring in polylogarithmic depth”, Quantum Inf. Comput.13, 937–962 (2013)

  54. [54]

    Beyond quantum supremacy: the hunt for useful quantum computers

    M. Brooks, “Beyond quantum supremacy: the hunt for useful quantum computers”, Nature 574, 19–22 (2019)

  55. [55]

    Quantum search by local adiabatic evolution

    J. Roland and N. J. Cerf, “Quantum search by local adiabatic evolution”, Phys. Rev. A65, 042308 (2002)

  56. [56]

    S. A. Adamson and P. Wallden,Adiabatic quantum unstructured search in parallel, Feb. 2025, arXiv:2502.08594 [quant-ph]

  57. [57]

    Addressing hard classical problems with Adiabatically Assisted Variational Quantum Eigensolvers

    A. Garcia-Saez and J. I. Latorre,Addressing hard classical problems with adiabatically assisted variational quantum eigensolvers, June 2018, arXiv:1806.02287 [quant-ph]

  58. [58]

    Improving the variational quantum eigensolver using variational adiabatic quantum computing

    S. M. Harwood, D. Trenev, S. T. Stober, P. Barkoutsos, T. P. Gujarati, S. Mostame, and D. Greenberg, “Improving the variational quantum eigensolver using variational adiabatic quantum computing”, ACM Transactions on Quantum Computing3, 1–20 (2022)

  59. [59]

    Simulatingadiabaticquantumcom- puting with parameterized quantum circuits

    I.Kolotouros,I.Petrongonas,M.Prokop,andP.Wallden,“Simulatingadiabaticquantumcom- puting with parameterized quantum circuits”, Quantum Science and Technology10, 015003 (2024)

  60. [60]

    M. E. Beverland, P. Murali, M. Troyer, K. M. Svore, T. Hoefler, V. Kliuchnikov, G. H. Low, M. Soeken, A. Sundaram, and A. Vaschillo,Assessing requirements to scale to practical quantum advantage, Nov. 2022, arXiv:2211.07629 [quant-ph]. 22