Erasure conversion in a high-fidelity Rydberg quantum simulator.

Minimizing and understanding errors is critical for quantum science, both in noisy intermediate scale quantum (NISQ) devices 1 and for the quest towards fault-tolerant quantum computation 2,3 . Rydberg arrays have emerged as a prominent platform in this context 4 with impressive system sizes 5,6 and proposals suggesting how error-correction thresholds could be significantly improved by detecting leakage errors with single-atom resolution 7,8 , a form of erasure error conversion 9-12 . However, two-qubit entanglement fidelities in Rydberg atom arrays 13,14 have lagged behind competitors 15,16 and this type of erasure conversion is yet to be realized for matter-based qubits in general. Here we demonstrate both erasure conversion and high-fidelity Bell state generation using a Rydberg quantum simulator 5,6,17,18 . When excising data with erasure errors observed via fast imaging of alkaline-earth atoms 19-22 , we achieve a Bell state fidelity of [Formula: see text], which improves to [Formula: see text] when correcting for remaining state-preparation errors. We further apply erasure conversion in a quantum simulation experiment for quasi-adiabatic preparation of long-range order across a quantum phase transition, and reveal the otherwise hidden impact of these errors on the simulation outcome. Our work demonstrates the capability for Rydberg-based entanglement to reach fidelities in the 0.999 regime, with higher fidelities a question of technical improvements, and shows how erasure conversion can be utilized in NISQ devices. These techniques could be translated directly to quantum-error-correction codes with the addition of long-lived qubits 7,22-24 .