- Open Access
End-to-End Quantum Algorithm for Nonlinear Fluid Dynamics with Bounded Quantum Advantage
PRX Quantum 7, 033060 – Published 18 September, 2026
DOI: https://doi.org/10.1103/xysy-q3fp
Abstract
Computational fluid dynamics (CFD) is a cornerstone of classical scientific computing, and there is growing interest in whether quantum computers can accelerate such simulations. The existing proposals for fault-tolerant quantum algorithms for CFD have almost exclusively been based on the Carleman embedding method, used to encode nonlinearities on a quantum computer. Here, we first identify several key challenges that must be addressed in order to establish quantum advantage using this method, including Carleman convergence, time-stepping requirements, condition-number scaling, and data extraction. Building on this analysis, we develop a novel algorithm for the incompressible lattice Boltzmann equation that addresses them and provide a detailed analysis, including all potential sources of algorithmic complexity and gate count estimates. We find that for an end-to-end problem, a modest quantum advantage may be preserved for selected observables in the high-error-tolerance regime. We establish a lower bound for the Reynolds number scaling of our quantum algorithm in dimension at Kolmogorov microscale resolution with , where is a multiplicative overhead for data extraction with for the drag force. This upper bounds the scaling improvement over classical algorithms by . However, our numerical investigations suggest a lower speedup, with a scaling estimate of for . Our results give robust evidence that small, but nontrivial, quantum advantages can be achieved in the context of CFD and motivate the need for additional rigorous end-to-end quantum algorithm development.
Physics Subject Headings (PhySH)
Popular Summary
Accurate simulation of fluid flows is critical across science and engineering, from predicting aerodynamic performance to understanding turbulent transport. However, high-fidelity computational fluid dynamics (CFD) remains one of the most resource-intensive tasks in classical computing. This has motivated interest in whether quantum computers could offer computational advantages in this field and bring transformative changes. Several recent approaches rely on Carleman linearization, a method that embeds nonlinear fluid equations into much higher-dimensional linear systems amenable to quantum computers. Despite the appeal of this approach, significant challenges remain unresolved, including convergence of the linearization procedure, run-time scaling for outputting the solution, and difficulties in extracting physically meaningful quantities from the quantum output. In this work, we introduce a new quantum algorithm for the lattice Boltzmann equation (LBE) that is designed explicitly to overcome these issues. By employing a shifted incompressible formulation of LBE together with a discrete Carleman embedding, we develop a representation of the dynamics that is compatible with fault-tolerant quantum computation while mitigating prior bottlenecks. We perform a comprehensive analysis of every component of the algorithm, down to the elementary-gate level, and quantify all sources of computational cost. This is complemented by extensive numerical studies assessing the validity and limitations of the underlying Carleman strategy. Our findings indicate that a modest but nontrivial quantum advantage is achievable for selected observables in specific parameter regimes. More broadly, this work provides a realistic and rigorous foundation for the emerging field of quantum-enabled CFD, clarifying both its potential and its fundamental limitations.
Article Text
References (86)
- P. Stefanin Volpiani, J.-B. Chapelier, A. Schwöppe, J. Jägersküpper, and S. Champagneux, Aircraft simulations using the new CFD software from ONERA, DLR, and Airbus, J. Aircr. 61, 857 (2024).
- H. Patel, T. Gerhold, and N. Ashton, Assessing the HPC performance of CODA for the NASA common research model, in AIAA Aviation Forum and Ascend 2024 (American Institute of Aeronautics and Astronautics (AIAA), Reston, VA, USA, 2024), p. 3792.
- P. R. Spalart, Strategies for turbulence modelling and simulations, Int. J. Heat Fluid Flow 21, 252 (2000).
- S. B. Pope, Turbulent Flows (Cambridge University Press, Cambridge, England, 2000).
- J. Appa, M. Turner, and N. Ashton, Performance of CPU and GPU HPC Architectures for off-design aircraft simulations, in AIAA Scitech 2021 Forum (American Institute of Aeronautics and Astronautics (AIAA), Reston, VA, USA, 2021), p. 0141.
- L. Lin, Lecture notes on quantum algorithms for scientific computation, arXiv:2201.08309.
- 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 (2019), pp. 193–204.
- S. Aaronson, Read the fine print, Nat. Phys. 11, 291 (2015).
- A. W. Harrow, A. Hassidim, and S. Lloyd, Quantum algorithm for linear systems of equations, Phys. Rev. Lett. 103, 150502 (2009).
- P. C. 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).
- D. Jennings, M. Lostaglio, S. Pallister, A. T. Sornborger, and Y. Subaşı, Randomized adiabatic quantum linear solver algorithm with optimal complexity scaling and detailed running costs, arXiv:2305.11352.
- A. M. Dalzell, A shortcut to an optimal quantum linear system solver, arXiv:2406.12086.
- M. E. Morales, L. Pira, P. Schleich, K. Koor, P. Costa, D. An, A. Aspuru-Guzik, L. Lin, P. Rebentrost, and D. W. Berry, Quantum linear system solvers: A survey of algorithms and applications, arXiv:2411.02522.
- D. W. Berry, High-order quantum algorithm for solving linear differential equations, J. Phys. A 47, 105301 (2014).
- A. Montanaro and S. Pallister, Quantum algorithms and the finite element method, Phys. Rev. A 93, 032324 (2016).
- D. W. Berry, A. M. Childs, A. Ostrander, and G. Wang, Quantum algorithm for linear differential equations with exponentially improved dependence on precision, Commun. Math. Phys. 356, 1057 (2017).
- P. C. S. Costa, S. Jordan, and A. Ostrander, Quantum algorithm for simulating the wave equation, Phys. Rev. A 99, 012323 (2019).
- N. Linden, A. Montanaro, and C. Shao, Quantum vs. classical algorithms for solving the heat equation, Commun. Math. Phys. 395, 601 (2022).
- D. W. Berry and P. C. Costa, Quantum algorithm for time-dependent differential equations using Dyson series, Quantum 8, 1369 (2024).
- A. Ameri, E. Ye, P. Cappellaro, H. Krovi, and N. F. Loureiro, Quantum algorithm for the linear Vlasov equation with collisions, Phys. Rev. A 107, 062412 (2023).
- D. Jennings, M. Lostaglio, R. B. Lowrie, S. Pallister, and A. T. Sornborger, The cost of solving linear differential equations on a quantum computer: Fast-forwarding to explicit resource counts, Quantum 8, 1553 (2024).
- R. P. Feynman, Feynman and Computation (CRC Press, Boca Raton, FL, USA, 2018), pp. 133–153.
- S. Lloyd, Universal quantum simulators, Science 273, 1073 (1996).
- D. W. Berry, G. Ahokas, R. Cleve, and B. C. Sanders, Efficient quantum algorithms for simulating sparse Hamiltonians, Commun. Math. Phys. 270, 359 (2007).
- A. Aspuru-Guzik, A. D. Dutoi, P. J. Love, and M. Head-Gordon, Simulated quantum computation of molecular energies, Science 309, 1704 (2005).
- S. McArdle, S. Endo, A. Aspuru-Guzik, S. C. Benjamin, and X. Yuan, Quantum computational chemistry, Rev. Mod. Phys. 92, 015003 (2020).
- 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).
- T. Carleman, Application de la théorie des équations intégrales linéaires aux systèmes d’équations différentielles non linéaires, Acta Math. 59, 63 (1932).
- M. Forets and A. Pouly, Explicit error bounds for Carleman linearization, arXiv:1711.02552.
- J.-P. Liu, H. Ø. Kolden, H. K. Krovi, N. F. Loureiro, K. Trivisa, and A. M. Childs, Efficient quantum algorithm for dissipative nonlinear differential equations, Proceed. Natl. Acad. Sci. 118, e2026805118 (2021).
- J.-P. Liu, D. An, D. Fang, J. Wang, G. H. Low, and S. Jordan, Efficient quantum algorithm for nonlinear reaction–diffusion equations and energy estimation, Commun. Math. Phys. 404, 963 (2023).
- H. Krovi, Improved quantum algorithms for linear and nonlinear differential equations, Quantum 7, 913 (2023).
- P. C. S. Costa, P. Schleich, M. E. S. Morales, and D. W. Berry, Further improving quantum algorithms for nonlinear differential equations via higher-order methods and rescaling, npj Quantum Inf. 11, 141 (2025).
- H.-C. Wu, J. Wang, and X. Li, Quantum algorithms for nonlinear dynamics: Revisiting Carleman linearization with no dissipative conditions, SIAM J. Sci. Comput. 47, A943 (2025).
- D. Jennings, K. Korzekwa, M. Lostaglio, A. T. Sornborger, Y. Subasi, and G. Wang, Quantum algorithms for general nonlinear dynamics based on the Carleman embedding, arXiv:2509.07155.
- W. Itani and S. Succi, Analysis of Carleman linearization of lattice Boltzmann, Fluids 7, 24 (2022).
- X. Li, X. Yin, N. Wiebe, J. Chun, G. K. Schenter, M. S. Cheung, and J. Mülmenstädt, Potential quantum advantage for simulation of fluid dynamics, Phys. Rev. Res. 7, 013036 (2025).
- J. Penuel, A. Katabarwa, P. D. Johnson, C. Farquhar, Y. Cao, and M. C. Garrett, Detailed assessment of calculating drag force with quantum computers: Explicit time-evolution precludes exponential advantage for nonlinear differential equations, arXiv:2406.06323.
- F. Turro, A. Lignarolo, and D. Dragoni, Toward practical application of the quantum Carleman lattice Boltzmann method in industrial CFD simulations, arXiv:2504.13033.
- C. Sanavio and S. Succi, Lattice Boltzmann–Carleman quantum algorithm and circuit for fluid flows at moderate Reynolds number, AVS Quantum Sci. 6, 023802 (2024).
- W. Itani, K. R. Sreenivasan, and S. Succi, Quantum algorithm for lattice Boltzmann (QALB) simulation of incompressible fluids with a nonlinear collision term, Phys. Fluids 36, 017112 (2024).
- C. Sanavio, W. A. Simon, A. Ralli, P. Love, and S. Succi, Carleman–lattice–Boltzmann quantum circuit with matrix access oracles, Phys. Fluids 37, 037123 (2025).
- T. Krüger, H. Kusumaatmaja, A. Kuzmin, O. Shardt, G. Silva, and E. M. Viggen, The Lattice Boltzmann Method: Principles and Practice (Springer, New York, 2016).
For other quantum approaches to CFD problems see Refs. [45, 46, 47, 48] or Sec. I of Ref. [41].
- S. Succi, W. Itani, K. Sreenivasan, and R. Steijl, Quantum computing for fluids: Where do we stand?, Europhys. Lett. 144, 10001 (2023).
- F. Tennie, S. Laizet, S. Lloyd, and L. Magri, Quantum computing for nonlinear differential equations and turbulence, Nat. Rev. Phys. 7, 220 (2025).
- Z. Meng, L. Chen, J.-P. Liu, and G. He, Toward end-to-end quantum simulation of rapidly distorted turbulence, arXiv:2511.18802.
- S. S. Bharadwaj and K. R. Sreenivasan, Hybrid quantum algorithms for flow problems, Proc. Natl. Acad. Sci. U. S. A. 120, e2311014120 (2023).
- X. He and L.-S. Luo, Lattice Boltzmann model for the incompressible Navier–Stokes equation, J. Stat. Phys. 88, 927 (1997).
- Z. Guo, B. Shi, and N. Wang, Lattice BGK model for incompressible Navier–Stokes equation, J. Comput. Phys. 165, 288 (2000).
- G. Berkolaiko, S. Rabinovich, and S. Havlin, Analysis of Carleman representation of analytical recursions, J. Math. Anal. Appl. 224, 81 (1998).
- S. Pruekprasert, T. Takisaka, C. Eberhart, A. Cetinkaya, and J. Dubut, Moment propagation of discrete-time stochastic polynomial systems using truncated Carleman linearization, IFAC-PapersOnLine 53, 14462 (2020).
- S. Pruekprasert, J. Dubut, T. Takisaka, C. Eberhart, and A. Cetinkaya, Moment propagation of polynomial systems through Carleman linearization for probabilistic safety analysis, Automatica 160, 111441 (2024).
- D. Jennings, K. Korzekwa, M. Lostaglio, P. Mannix, R. Ashworth, E. Marsili, and S. Rolston, Simulating non-trivial incompressible flows with a quantum lattice Boltzmann algorithm, arXiv:2512.05781.
We focus on the QLS-based route, represented by Refs. [37, 38, 39], because it is the setting in which end-to-end complexity cost has been analyzed. By contrast, Refs. [40, 41, 42] focus on Carleman embedding for a single time step of the LBE evolution, without addressing its integration into a full time-evolution algorithm.
- Z. Guo and C. Shu, Lattice Boltzmann Method and Its Application in Engineering (World Scientific, Singapore, 2013), Vol. 3.
- S. Ubertini, G. Bella, and S. Succi, Unstructured lattice Boltzmann equation with memory, Math. Comput. Simul. 72, 237 (2006).
- S. Ubertini, P. Asinari, and S. Succi, Three ways to lattice Boltzmann: A unified time-marching picture, Phys. Rev. E 81, 016311 (2010).
While sizes corresponding to Carleman systems for high-impact uses-cases would be much larger, and beyond the reach of classical hardware for the foreseeable future, these are—to our knowledge—the largest numerical simulations ever done to establish the scaling of Carleman-based algorithms for fluids (and in fact, for Carleman-based algorithms more generally).
- S. Succi, The Lattice Boltzmann Equation: for Fluid Dynamics and beyond (Oxford University Press, New York, 2001).
- P. L. Bhatnagar, E. P. Gross, and M. Krook, A model for collision processes in gases. I. Small amplitude processes in charged and neutral one-component systems, Phys. Rev. 94, 511 (1954).
- X. He, X. Shan, and G. D. Doolen, Discrete Boltzmann equation model for nonideal gases, Phys. Rev. E 57, R13 (1998).
- X. He, S. Chen, and G. D. Doolen, A novel thermal model for the lattice Boltzmann method in incompressible limit, J. Comput. Phys. 146, 282 (1998).
- D. An, A. Onwunta, and G. Yang, Fast-forwarding quantum algorithms for linear dissipative differential equations, arXiv:2410.13189.
- D. W. Berry, A. M. Childs, R. Cleve, R. Kothari, and R. D. Somma, Simulating Hamiltonian dynamics with a truncated Taylor series, Phys. Rev. Lett. 114, 090502 (2015).
This limitation could potentially be handled via a different algorithm implementing an “interaction picture” in the frame of streaming, but this would require further analysis.
for any satisfying the Lyapunov condition , where is the condition number of . The parameter can bring in an -dependence.
- C. R. Doering and J. D. Gibbon, Applied Analysis of the Navier-Stokes Equations (Cambridge university press, Cambridge, England, 1995), Vol. 12.
- F. J. Higuera and S. Succi, Simulating the flow around a circular cylinder with a lattice Boltzmann equation, Europhys. Lett. 8, 517 (1989).
- R. Benzi, S. Succi, and M. Vergassola, The lattice Boltzmann equation: Theory and applications, Phys. Rep. 222, 145 (1992).
- G. Silva and V. Semiao, First-and second-order forcing expansions in a lattice Boltzmann method reproducing isothermal hydrodynamics in artificial compressibility form, J. Fluid Mech. 698, 282 (2012).
Also note that one can improve this constant probability quadratically by using amplitude amplification.
- J. Lemieux, M. Lostaglio, S. Pallister, W. Pol, K. Seetharam, S. Sim, and B. Şahinoğlu, Quantum sampling algorithms for quantum state preparation and matrix block-encoding, arXiv:2405.11436.
For a system with , assuming spatial resolution parameter to resolve the Kolmogorov microscale, the Carleman vector for the smallest nontrivial truncation order has dimension approximately equal to . Assuming each entry is stored as a double precision real number taking 8 bytes, it means that the Carleman vector takes up roughly 6.2 terabytes.
- I. Novikau and I. Joseph, Globalizing the Carleman linear embedding method for nonlinear dynamics, arXiv:2510.15715.
Note, however, that it is not a priori clear what implications this would have for the attainment of a statistical steady state of fluid turbulence [77].
- L. Cappelli and S. Succi, Lowest order Carleman linearization for low Reynolds long-term behaviour of fluid flow simulations, arXiv:2605.23380.
- I. Delbende and M. Rossi, The dynamics of a viscous vortex dipole, Phys. Fluids 21, 073605 (2009).
- D. W. Berry, M. Kieferová, A. Scherer, Y. R. Sanders, G. H. Low, N. Wiebe, C. Gidney, and R. Babbush, Improved techniques for preparing eigenstates of fermionic Hamiltonians, npj Quantum Inf. 4, 22 (2018).
- P. Selinger, A meet-in-the-middle algorithm for fast synthesis of depth-optimal quantum circuits, Phys. Rev. A 87, 042302 (2013).
- M. Amy, D. Maslov, M. Mosca, and M. Roetteler, Rise of conditionally clean ancillae for efficient quantum circuit constructions, IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst. 32, 818 (2013).
- T. Khattar and C. Gidney, Rise of conditionally clean ancillae for efficient quantum circuit constructions, Quantum 9, 1752 (2025).
- N. J. Ross and P. Selinger, Optimal ancilla-free Clifford+ approximation of -rotations, arXiv:1403.2975.
- M. Mottonen, J. J. Vartiainen, V. Bergholm, and M. M. Salomaa, Transformation of quantum states using uniformly controlled rotations, arXiv:quant-ph/0407010.
- C. Gidney, Halving the cost of quantum addition, Quantum 2, 74 (2018).
- V. Kliuchnikov, Synthesis of unitaries with Clifford+ circuits, arXiv:1306.3200.
