- Open Access
Quantum community detection via deterministic elimination
Phys. Rev. A 112, 052422 – Published 12 November, 2025
DOI: https://doi.org/10.1103/s7cm-c9qy
Abstract
We propose a quantum algorithm for calculating the structural properties of complex networks and graphs. The corresponding protocol—deteQt—is designed to perform large-scale community and botnet detection, where a specific subgraph of a larger graph is identified based on its properties. We construct a workflow relying on ground state preparation of the network modularity matrix or graph Laplacian. The corresponding maximum modularity vector is encoded into a -qubit register that contains community information. We develop a strategy for “signing” this vector via quantum signal processing, such that it closely resembles a hypergraph state, and project it onto a suitable linear combination of such states to detect botnets. As part of the workflow, and of potential independent interest, we present a readout technique that allows filtering out the incorrect solutions deterministically. This can reduce the scaling for the number of samples from exponential to polynomial. The approach serves as a building block for graph analysis with quantum speedup and enables the cybersecurity of large-scale networks.
Physics Subject Headings (PhySH)
Article Text
References (84)
- S. Aaronson, Quantum Computing Since Democritus (Cambridge University Press, Cambridge, 2013).
- S. McArdle, S. Endo, A. Aspuru-Guzik, S. C. Benjamin, and X. Yuan, Quantum computational chemistry, Rev. Mod. Phys. 92, 015003 (2020).
- Y. Alexeev et al., Quantum-centric supercomputing for materials science: A perspective on challenges and future directions, Future Gener. Comput. Syst. 160, 666 (2024).
- D. R. Simon, On the power of quantum computation, SIAM J. Comput. 26, 1474 (1997),.
- S. Aaronson, BQP and the polynomial hierarchy, in Proceedings of the Forty-Second ACM Symposium on Theory of Computing, STOC '10 (Association for Computing Machinery, New York, 2010), p. 141–150.
- P. W. Shor, Polynomial-time algorithms for prime factorization and discrete logarithms on a quantum computer, SIAM J. Comput. 26, 1484 (1997).
- A. W. Harrow, A. Hassidim, and S. Lloyd, Quantum algorithm for linear systems of equations, Phys. Rev. Lett. 103, 150502 (2009).
- A. M. Childs, R. Kothari, and R. D. Somma, Quantum algorithm for systems of linear equations with exponentially improved dependence on precision, SIAM J. Comput. 46, 1920 (2017).
- L. Lin and Y. Tong, Optimal polynomial based quantum eigenstate filtering with application to solving quantum linear systems, Quantum 4, 361 (2020).
- Y. Subaşı, R. D. Somma, and D. Orsucci, Quantum algorithms for systems of linear equations inspired by adiabatic quantum computing, Phys. Rev. Lett. 122, 060504 (2019).
- S. Chakraborty, Implementing any linear combination of unitaries on intermediate-term quantum computers, Quantum 8, 1496 (2024).
- P. C. S. Costa, D. An, Y. R. Sanders, Y. Su, R. Babbush, and D. W. Berry, Optimal scaling quantum linear-systems solver via discrete adiabatic theorem, PRX Quantum 3, 040303 (2022).
- C. A. Williams, A. A. Gentile, V. E. Elfving, D. Berger, and O. Kyriienko, Quantum iterative methods for solving differential equations with application to computational fluid dynamics arXiv:2404.08605.
- N. Linden, A. Montanaro, and C. Shao, Quantum vs classical algorithms for solving the heat equation arXiv:2004.06516.
- J. Biamonte, P. Wittek, N. Pancotti, P. Rebentrost, N. Wiebe, and S. Lloyd, Quantum machine learning, Nature (London) 549, 195 (2017).
- F. Arute, K. Arya, R. Babbush, D. Bacon, J. C. Bardin, R. Barends, R. Biswas, S. Boixo, F. G. S. L. Brandao, D. A. Buell et al., Quantum supremacy using a programmable superconducting processor, Nature (London) 574, 505 (2019).
- D. Hangleiter and J. Eisert, Computational advantage of quantum random sampling, Rev. Mod. Phys. 95, 035001 (2023).
- C. Zoufal, A. Lucchi, and S. Woerner, Quantum generative adversarial networks for learning and loading random distributions, npj Quantum Inf. 5, 103 (2019).
- B. Coyle, D. Mills, V. Danos, and E. Kashefi, The born supremacy: Quantum advantage and training of an Ising born machine, npj Quantum Inf. 6, 60 (2020).
- A. E. Paine, V. E. Elfving, and O. Kyriienko, Quantum quantile mechanics: Solving stochastic differential equations for generating time-series, Adv. Quantum Technol. 6, 2300065 (2023).
- O. Kyriienko, A. E. Paine, and V. E. Elfving, Protocols for trainable and differentiable quantum generative modeling, Phys. Rev. Res. 6, 033291 (2024).
- S. Kasture, O. Kyriienko, and V. E. Elfving, Protocols for classically training quantum generative models on probability distributions, Phys. Rev. A 108, 042406 (2023).
- H.-Y. Wu, V. E. Elfving, and O. Kyriienko, Multidimensional quantum generative modeling by quantum Hartley transform, Adv. Quantum Technol. 8, 2400337 (2025).
- A. Abbas, A. Ambainis, B. Augustino, A. Bärtschi, H. Buhrman, C. Coffrin, G. Cortiana, V. Dunjko, D. J. Egger, B. G. Elmegreen, N. Franco, F. Fratini, B. Fuller, J. Gacon, C. Gonciulea, S. Gribling, S. Gupta, S. Hadfield, R. Heese, G. Kircher et al., Challenges and opportunities in quantum optimization, Nat. Rev. Phys. 6, 718 (2024).
- L. Zhou, S.-T. Wang, S. Choi, H. Pichler, and M. D. Lukin, Quantum approximate optimization algorithm: Performance, mechanism, and implementation on near-term devices, Phys. Rev. X 10, 021067 (2020).
- S. Ebadi, A. Keesling, M. Cain, T. T. Wang, H. Levine, D. Bluvstein, G. Semeghini, A. Omran, J.-G. Liu, R. Samajdar et al., Quantum optimization of maximum independent set using Rydberg atom arrays, Science 376, 1209 (2022).
- L. Zhu, H. L. Tang, G. S. Barron, F. A. Calderon-Vargas, N. J. Mayhall, E. Barnes, and S. E. Economou, Adaptive quantum approximate optimization algorithm for solving combinatorial problems on a quantum computer, Phys. Rev. Res. 4, 033029 (2022).
- S. P. Jordan, N. Shutty, M. Wootters, A. Zalcman, A. Schmidhuber, R. King, S. V. Isakov, and R. Babbush, Optimization by decoded quantum interferometry, Nature (London) 646, 831 (2025).
- Edelsbrunner, Letscher, and Zomorodian, Topological persistence and simplification, Discrete Comput. Geom. 28, 511 (2002).
- A. Zomorodian and G. Carlsson, Computing persistent homology, Discrete Comput. Geom. 33, 249 (2005).
- G. Carlsson, Topology and data, Bull. Am. Math. Soc. 46, 255 (2009).
- L. Wasserman, Topological data analysis, Annu. Rev. Stat. Appl. 5, 501 (2018).
- F. Chazal and B. Michel, An introduction to topological data analysis: Fundamental and practical aspects for data scientists, Front. Artif. Intell. 4, 667963 (2021).
- S. Lloyd, S. Garnerone, and P. Zanardi, Quantum algorithms for topological and geometric analysis of data, Nat. Commun. 7, 10138 (2016).
- C. Gyurik, C. Cade, and V. Dunjko, Towards quantum advantage via topological data analysis, Quantum 6, 855 (2022).
- D. W. Berry, Y. Su, C. Gyurik, R. King, J. Basso, A. Del Toro Barba, A. Rajput, N. Wiebe, V. Dunjko, and R. Babbush, Analyzing prospects for quantum advantage in topological data analysis, PRX Quantum 5, 010319 (2024).
- S. Scali, C. Umeano, and O. Kyriienko, Quantum topological data analysis via the estimation of the density of states, Phys. Rev. A 110, 042616 (2024).
- S. Scali, C. Umeano, and O. Kyriienko, The topology of data hides in quantum thermal states, APL Quantum 1, 036106 (2024).
- I. Y. Akhalwaya, S. Ubaru, K. L. Clarkson, M. S. Squillante, V. Jejjala, Y.-H. He, K. Naidoo, V. Kalantzis, and L. Horesh, Topological data analysis on noisy quantum computers, arXiv:2209.09371.
- C. Dürr, M. Heiligman, P. HOyer, and M. Mhalla, Quantum query complexity of some graph problems, SIAM J. Comput. 35, 1310 (2006).
- T. Krauss and J. McCollum, Solving the network shortest path problem on a quantum annealer, IEEE Trans. Quantum Eng. 1, 1 (2020).
- G. Chapuis, H. Djidjev, G. Hahn, and G. Rizk, Finding maximum cliques on a quantum annealer, in Proceedings of the Computing Frontiers Conference, CF '17 (ACM, New York, 2017), pp. 63–70.
- J. M. Arrazola and T. R. Bromley, Using Gaussian boson sampling to find dense subgraphs, Phys. Rev. Lett. 121, 030503 (2018).
- L. Banchi, M. Fingerhuth, T. Babej, C. Ing, and J. M. Arrazola, Molecular docking with Gaussian boson sampling, Sci. Adv. 6, eaax1950 (2020).
- S. Yu, Z.-P. Zhong, Y. Fang, R. B. Patel, Q.-P. Li, W. Liu, Z. Li, L. Xu, S. Sagona-Stophel, E. Mer, S. E. Thomas, Y. Meng, Z.-P. Li, Y.-Z. Yang, Z.-A. Wang, N.-J. Guo, W.-H. Zhang, G. K. Tranmer, Y. Dong, Y.-T. Wang et al., A universal programmable Gaussian boson sampler for drug discovery, Nat. Comput. Sci. 3, 839 (2023).
- A. M. Childs, R. Cleve, E. Deotto, E. Farhi, S. Gutmann, and D. A. Spielman, Exponential algorithmic speedup by a quantum walk, in Proceedings of the Thirty-Fifth Annual ACM Symposium on Theory of Computing, STOC '03 (Association for Computing Machinery, New York, 2003), pp. 59–68.
- R. Babbush, D. W. Berry, R. Kothari, R. D. Somma, and N. Wiebe, Exponential quantum speedup in simulating coupled classical oscillators, Phys. Rev. X 13, 041041 (2023).
- S. H. Strogatz, Exploring complex networks, Nature (London) 410, 268 (2001).
- R. Albert and A.-L. Barabási, Statistical mechanics of complex networks, Rev. Mod. Phys. 74, 47 (2002).
- S. Boccaletti, V. Latora, Y. Moreno, M. Chavez, and D.-U. Hwang, Complex networks: Structure and dynamics, Phys. Rep. 424, 175 (2006).
- M. Bardoscia, P. Barucca, S. Battiston, F. Caccioli, G. Cimini, D. Garlaschelli, F. Saracco, T. Squartini, and G. Caldarelli, The physics of financial networks, Nat. Rev. Phys. 3, 490 (2021).
- S. Fortunato, Community detection in graphs, Phys. Rep. 486, 75 (2010).
- H. Liao, M. S. Mariani, M. Medo, Y.-C. Zhang, and M.-Y. Zhou, Ranking in evolving complex networks, Phys. Rep. 689, 1 (2017).
- E. de Silva and M. P. Stumpf, Complex networks and simple models in biology, J. R. Soc. Interface. 2, 419 (2005).
- E. J. Deeds, J. Krivine, J. Feret, V. Danos, and W. Fontana, Combinatorial complexity and compositional drift in protein interaction networks, PLoS ONE 7, e32032 (2012).
- W. He, W. Xu, X. Ge, Q.-L. Han, W. Du, and F. Qian, Secure control of multiagent systems against malicious attacks: A brief survey, IEEE Trans. Indust. Inf. 18, 3595 (2022).
- S. Klamt and J. Stelling, Combinatorial complexity of pathway analysis in metabolic networks, Mol. Biol. Rep. 29, 233 (2002).
- J. Biamonte, M. Faccin, and M. De Domenico, Complex networks from classical to quantum, Commun. Phys. 2, 53 (2019).
- M. E. J. Newman and M. Girvan, Finding and evaluating community structure in networks, Phys. Rev. E 69, 026113 (2004).
- M. E. J. Newman, Modularity and community structure in networks, Proc. Natl. Acad. Sci. USA 103, 8577 (2006).
- U. von Luxburg, A tutorial on spectral clustering, Stat. Comput. 17, 395 (2007).
- L. Kučera, Expected complexity of graph partitioning problems, Discrete Appl. Math. 57, 193 (1995).
- A. Buluç, H. Meyerhenke, I. Safro, P. Sanders, and C. Schulz, Recent advances in graph partitioning, in Algorithm Engineering (Springer International Publishing, Berlin, 2016), pp. 117–158.
- K. Andreev and H. Räcke, Balanced graph partitioning, in Proceedings of the Sixteenth Annual ACM Symposium on Parallelism in Algorithms and Architectures, SPAA04 (ACM, New York, 2004), pp. 120–124.
- B. Hendrickson and T. G. Kolda, Graph partitioning models for parallel computing, Parallel Comput. 26, 1519 (2000).
- A. B. Kahng, J. Lienig, I. L. Markov, and J. Hu, VLSI Physical Design: From Graph Partitioning to Timing Closure (Springer International Publishing, Berlin, 2022).
- S. V. Patil and D. B. Kulkarni, K-way spectral graph partitioning for load balancing in parallel computing, Int. J. Inf. Technol. 13, 1893 (2021).
- P. De Meo, E. Ferrara, G. Fiumara, and A. Provetti, Generalized louvain method for community detection in large networks, in 2011 11th International Conference on Intelligent Systems Design and Applications (IEEE, New York, 2011), pp. 88–93.
- S. Van Dongen, Graph clustering via a discrete uncoupling process, SIAM J. Matrix Anal. Appl. 30, 121 (2008).
- A. Gilyén, Y. Su, G. H. Low, and N. Wiebe, Quantum singular value transformation and beyond: Exponential improvements for quantum matrix arithmetics, in Proceedings of the 51st Annual ACM SIGACT Symposium on Theory of Computing, STOC '19 (ACM, New York, 2019).
- R. Qu and Y. Bao, Quantum entanglement in -qubit real equally weighted states, arXiv:1207.2518.
- 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 (Association for Computing Machinery, New York, 1996), pp. 212–219.
- D. Deutsch and R. Jozsa, Rapid solution of problems by quantum computation, Proc. R. Soc. Lond. A 439, 553 (1992).
- G. H. Low and I. L. Chuang, Hamiltonian simulation by qubitization, Quantum 3, 163 (2019).
- M. Cerezo, A. Arrasmith, R. Babbush, S. C. Benjamin, S. Endo, K. Fujii, J. R. McClean, K. Mitarai, X. Yuan, L. Cincio, and P. J. Coles, Variational quantum algorithms, Nat. Rev. Phys. 3, 625 (2021).
- A. G. Rattew and P. Rebentrost, Nonlinear transformations of quantum amplitudes: Exponential improvement, generalization, and applications, arXiv:2309.09839.
- M. Rossi, M. Huber, D. Bruß, and C. Macchiavello, Quantum hypergraph states, New J. Phys. 15, 113022 (2013).
- H. Alghassi, A. Deshmukh, N. Ibrahim, N. Robles, S. Woerner, and C. Zoufal, A variational quantum algorithm for the Feynman-Kac formula, Quantum 6, 730 (2022).
- C. Umeano, V. E. Elfving, and O. Kyriienko, Geometric quantum machine learning of protocols and latent graph classifiers, arXiv:2402.03871.
- S. Scali and C. Umeano, Qu-dos/dataset-communitydetection: Zenodo (2025), https://zenodo.org/records/17370413.
- Y. Dong, X. Meng, K. B. Whaley, and L. Lin, Efficient phase-factor evaluation in quantum signal processing, Phys. Rev. A 103, 042419 (2021).
- J. M. Martyn, Z. M. Rossi, A. K. Tan, and I. L. Chuang, Grand unification of quantum algorithms, PRX Quantum 2, 040203 (2021).
- G. H. Low and I. L. Chuang, Optimal Hamiltonian simulation by quantum signal processing, Phys. Rev. Lett. 118, 010501 (2017).
- K. Mizuta and K. Fujii, Recursive quantum eigenvalue and singular-value transformation: Analytic construction of matrix sign function by Newton iteration, Phys. Rev. Res. 6, L012007 (2024).