aiqbench analysis
This research addresses a fundamental unitarity challenge in quantum lattice Boltzmann methods by replacing non-unitary BGK relaxation with a rotation operator, enabling gate-level circuit construction for fluid dynamics simulations. The approach successfully validates accuracy across D2Q5 and D2Q9 models, offering a scalable framework for simulating convection-diffusion and Navier-Stokes equations on quantum hardware.
Rotation Collision based Quantum Lattice Boltzmann Methods
arXiv:2609.16721v1 Announce Type: cross Abstract: In the existing quantum algorithms for the lattice Boltzmann method, resolving the unitarity problem of the BGK collision operator from first principles remains a fundamental challenge, and a systematically constructed unitary alternative that reproduces the BGK relaxation structure to leading order has not yet been established in the literature. In this work, we propose a novel quantum lattice Boltzmann method (QLBM) based on the rotation collision operator, in which the non-unitary BGK relaxation is replaced by a unitary rotation in the amplitude space of the distribution function, and the corresponding gate-level quantum circuits are also constructed. Specifically, the rotation collision operator is developed for both the D2Q5 model of the convection-diffusion equation and the D2Q9 model of the incompressible Navier--Stokes equations. It is worth noting that, for the D2Q5 model, the equilibrium-state preparation circuit can be precompiled and reused, and the resulting unitary blocks can be sequentially composed once the state-dependent collision parameters are specified. Finally, some numerical experiments are performed to validate the developed QLBM, demonstrating its accuracy and effectiveness.
Abstract:In the existing quantum algorithms for the lattice Boltzmann method, resolving the unitarity problem of the BGK collision operator from first principles remains a fundamental challenge, and a systematically constructed unitary alternative that reproduces the BGK relaxation structure to leading order has not yet been established in the literature. In this work, we propose a novel quantum lattice Boltzmann method (QLBM) based on the rotation collision operator, in which the non-unitary BGK relaxation is replaced by a unitary rotation in the amplitude space of the distribution function, and the corresponding gate-level quantum circuits are also constructed. Specifically, the rotation collision operator is developed for both the D2Q5 model of the convection-diffusion equation and the D2Q9 model of the incompressible Navier--Stokes equations. It is worth noting that, for the D2Q5 model, the equilibrium-state preparation circuit can be precompiled and reused, and the resulting unitary blocks can be sequentially composed once the state-dependent collision parameters are specified. Finally, some numerical experiments are performed to validate the developed QLBM, demonstrating its accuracy and effectiveness.
15 pages, 5 figures. Submitted to SIAM Journal on Scientific Computing
Fluid Dynamics (physics.flu-dyn); Quantum Physics (quant-ph)
arXiv:2609.16721 [physics.flu-dyn]
(or arXiv:2609.16721v1 [physics.flu-dyn] for this version)
https://doi.org/10.48550/arXiv.2609.16721 Focus to learn more arXiv-issued DOI via DataCite (pending registration)
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Full text under the publisher's open licence · 279 words
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