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arXiv · 2606.20123

QPU-scale randomized benchmarking via Bell-pair injection

Haripriya Pettugani·María Aguado-Yáñez·Astryd Park·Daniel Bultrini·James R. Wootton
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Abstract

Mirror randomized benchmarking (MRB) is an established technique that provides a global error metric at the scale of a whole QPU. To expand upon this we introduce Mirror Quantum Awesomeness (MQA), a hybrid protocol that adds a structured entangling layer to MRB circuits. This enables per-edge correlation dynamics to be tracked via mutual information while preserving the MRB infidelity estimate. The resulting analysis of the injected entangled pairs locates a critical circuit depth, beyond which rudimentary error mitigation techniques can be expected to fail. A topological variant, Topological MQA, supplies a second critical depth via a decoder based on the surface-code decoding problem. Both are validated in simulation and demonstrated on the 156-qubit \texttt{ibm\_fez} and \texttt{ibm\_kingston} processors, where MQA closely agrees with MRB on the entanglement infidelity and the critical depth for \texttt{ibm\_fez} is found to be $\sim 50$.

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Haripriya Pettugani, María Aguado-Yáñez, Astryd Park, Daniel Bultrini, James R. Wootton. 2026-06-18. QPU-scale randomized benchmarking via Bell-pair injection. https://arxiv.org/abs/2606.20123

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