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arXiv · 2607.20409

Efficiently Simulable Pauli Correlation Encoding

Daniele Lizzio Bosco·Gabriel Matos·Chen-Yu Liu·Frederic Rapp·Fabian Finger·Enrico Rinaldi·Konstantinos Meichanetzidis
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Abstract

Pauli Correlation Encoding (PCE) is a heuristic framework for binary optimisation that encodes classical variables into many-body Pauli observables. While PCE requires fewer qubits than other approaches, it relies on estimating a large number of Pauli expectation values whose signs determine the variables' values, which can incur substantial measurement overhead. Here, we introduce efficiently simulable PCE, a class of dequantised PCE realisations where all expectation values needed can be computed efficiently classically. We instantiate this idea using free-fermionic evolutions, realised by matchgate circuits, and Instantaneous Quantum Polynomial (IQP) circuits. On MaxCut, Maximum Independent Set, Multi-Dimensional Knapsack, and Max3SAT benchmarks, these methods produce high-quality solutions across problem sizes ranging from tens to thousands of variables. Our results show that PCE is naturally understood as a correlation-based optimisation framework with both quantum and classically simulable realisations. This yields a dequantised baseline for evaluating future quantum PCE implementations.

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Daniele Lizzio Bosco, Gabriel Matos, Chen-Yu Liu, Frederic Rapp, Fabian Finger, Enrico Rinaldi, Konstantinos Meichanetzidis. 2026-07-22. Efficiently Simulable Pauli Correlation Encoding. https://arxiv.org/abs/2607.20409

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