2025/10/28 by Gleb Kalachev, Pavel Mosharev, P. A. Mosharev +9 · 3 voices
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum many-body systems #quant-ph
paper · pdf · doi:10.22331/q-2026-07-23-2173
openalex publication_date 2026/07/23 · rss pubdate 2026/07/23 · openalex created_date 2026/07/24 · openalex updated_date 2026/08/01
Quantum 10, 2173 (2026). 10.22331/q-2026-07-23-2173 Quantum circuit simulators running on classical computers offer a vital platform for designing, testing, and optimizing quantum algorithms, driving innovation despite limited access to real quantum hardware. However, their scalability is inherently constrained by exponential memory and computational overhead, which restricts accurate simulation of large-scale quantum circuits and often results in approximate output distributions. Here, we propose an exact sampling algorithm that integrates tensor network contraction techniques with a Markov process, wherein a classical state evolves according to the local structure of the quantum circuit. As a demonstration, we target the challenge of generating samples from ideal and noisy QAOA circuits with up to 476 qubits, incorporating both depolarizing and amplitude damping noise models. These results enable further validation of several assumptions and conjectures at a scale previously out of reach, significantly expanding the scope of classical simulation in quantum algorithm research.