ORNL Develops LuGo Algorithm on Frontier Supercomputer, Reducing Quantum Circuit Gate Counts by 95% for Computational Fluid Dynamics

Computational scientists at the Oak Ridge National Laboratory (ORNL) have introduced LuGo, an enhanced Quantum Phase Estimation (QPE) algorithmic framework designed to mitigate circuit-depth bottlenecks in quantum computational fluid dynamics (CFD). Developed using the Department of Energy's (DOE) Frontier exascale supercomputer at the Oak Ridge Leadership Computing Facility (OLCF) and validated via the Quantum Computing User Program (QCUP), the algorithm achieves a greater than 95% reduction in total quantum gate operations required to solve fluid flow differential equations.

A primary bottleneck in applying the Harrow-Hassidim-Lloyd (HHL) quantum linear system solver to fluid dynamics—such as the Hele-Shaw flow equation governing viscous fluids between parallel plates—is the high circuit depth associated with conventional QPE encoding. Standard implementations for these fluid equations required approximately 2,000,000 logic gates, introducing severe noise and decoherence risks. LuGo restructures the hybrid workflow by shifting heavy initialization routines onto classical HPC nodes prior to quantum state mapping. By performing classical preprocessing on a single node of the 2-exaflop Frontier system, the team compressed the required quantum gate count down to 91,000 gates.

The team validated LuGo across multiple commercial quantum hardware platforms provided through the DOE Quantum User Expansion for Science and Technology (QUEST) initiative. Experimental evaluations were executed on Quantinuum’s H-1 trapped-ion processor alongside IBM (Marrakesh, Sherbrooke) and IQM (Garnet, Sirius) superconducting devices. Shifting the data-transformation load to classical pre-processing provides a practical route toward executing high-dimensional fluid, aerodynamics, microfluidics, and groundwater flow simulations on early error-corrected and error-mitigated quantum processors.

Review the full laboratory release on the Oak Ridge Leadership Computing Facility Newsroom here, inspect the peer-reviewed research manuscript in Future Generation Computer Systems here, examine comprehensive academic literature via the Quantum Algorithms for CFD Review on arXiv here, and read our previous coverage on the Department of Energy's national laboratory quantum access calls here.

October 2, 2026