Quantum Inspiration, Classical Advantage: A Dequantized Particle Algorithm for the Nonlinear Vlasov–Poisson System

Today’s quantum computers cannot yet simulate the hot plasmas in fusion reactors. However, by examining how quantum algorithms approach these challenges, we can dequantize their core ideas into streamlined, high-performance algorithms that run on today’s conventional hardware. This quantum-inspired research uncovers more efficient algorithmic structures for fusion plasmas, which—when adapted for classical computers—offer high accuracy with reduced cost. We present a dequantized particle algorithm for the nonlinear Vlasov–Poisson (VP) system, derived by dequantizing the underlying many-body quantum theory. Unlike traditional VP algorithms in 6D phase space, this method operates in 3D configuration space and exactly preserves conservation laws at the discrete level. As a demonstration, the classical nonlinear two-stream instability is simulated in one spatial dimension using only 97 dequantized particles, accurately reproducing the theoretical linear growth rate and phase-space vortex formation, with conservation laws maintained over long integration times. Dequantized particle algorithms provide a compact, efficient alternative for high-fidelity plasma kinetic modeling on classical computers and pave the way for future quantum algorithms for plasma simulations.