Dynamical simulations of many-body quantum chaos on a quantum computer

Abstract

Quantum circuits with local unitaries offer a platform to explore many-body quantum dynamics in discrete time. Their locality makes them suitable for current processors, but verification at scale is difficult for non-integrable systems. Here we study dual-unitary circuits, which are maximally chaotic yet permit exact analytical solutions for certain correlation functions. Using improved noise-learning and error-mitigation methods, we show that a superconducting quantum processor with 91 qubits is able to accurately simulate these correlators. We then perturb the circuits away from the dual-unitary point and benchmark the dynamics against tensor-network simulations. These results establish error-mitigated digital quantum simulation on pre-fault-tolerant processors as a reliable tool to explore emergent quantum many-body phases. Studying many-body quantum chaos on current quantum hardware is hindered by noise and limited scalability. Now it is shown that a superconducting processor, combined with error mitigation, can accurately simulate dual-unitary circuit dynamics.