Simulating quantum systems on classical hardware is a long-standing challenge, as the required resources grow exponentially with system size. In this talk, “The Pauli Propagation Algorithm: A Classical Approach to Simulating Quantum Systems”, I will explain why such simulations are difficult and introduce the Pauli Propagation Algorithm (PPA) — a classical method that works in the Heisenberg picture to efficiently track the evolution of Pauli observables while keeping only a tractable subset of terms. This approach has enabled state-of-the-art classical simulations of complex systems, including the 3D Ising model (PRX Quantum 6, 020302), and was instrumental in critically reassessing a claimed quantum supremacy experiment (arXiv:2308.05077).
Ana Martín y Francesco Paolo Di Meglio