2026/06/18 by Haripriya Pettugani, María Aguado-Yáñez, Astryd Park +2 · 1 voice
Physics and Astronomy · #quant-ph
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 ibm_fez and ibm_kingston processors, where MQA closely agrees with MRB on the entanglement infidelity and the critical depth for ibm_fez is found to be ∼ 50.