Error-Mitigated Quantum Routing on Noisy Devices

TL;DR

This paper demonstrates that combining error mitigation techniques on noisy quantum devices significantly improves quantum routing fidelity, enabling practical quantum communication protocols without quantum error correction.

Contribution

It introduces the experimental application of concatenated error mitigation methods, ZNE and PEC, to quantum routing on a 7-qubit IBM device, achieving near-perfect fidelity.

Findings

Concatenated error mitigation greatly enhances routing fidelity.

Quantum routing becomes feasible on noisy devices with error mitigation.

Almost perfect entangled path fidelity achieved.

Abstract

With sub-threshold quantum error correction on quantum hardware still out of reach, quantum error mitigation methods are currently deemed an attractive option for implementing certain applications on near-term noisy quantum devices. One such application is quantum routing - the ability to map an incoming quantum signal into a superposition of paths. In this work, we use a 7-qubit IBM quantum device to experimentally deploy two promising quantum error mitigation methods, Zero-Noise Extrapolation (ZNE) and Probabilistic Error Cancellation (PEC), in the context of quantum routing. Importantly, beyond investigating the improved performance of quantum routing via ZNE and PEC separately, we also investigate the routing performance provided by the concatenation of these two error-mitigation methods. Our experimental results demonstrate that such concatenation leads a very significant performance improvement relative to implementation with no error mitigation. Indeed, an almost perfect performance in terms of fidelity of the output entangled paths is found. These new results reveal that with concatenated quantum error-mitigation embedded, useful quantum routing becomes feasible on current devices without the need for quantum error correction - opening up a potential implementation pathway to other applications that utilize a superposition of communication links.