Robustness of channel-adapted quantum error correction

TL;DR

This paper investigates the robustness of channel-adapted quantum error correction, showing that such tailored methods outperform others in maintaining fidelity despite unexpected channel uncertainties.

Contribution

It demonstrates that channel-adapted quantum error correction is more robust against uncertainties than generic methods, with results applicable to Pauli channels and stabilizer codes.

Findings

Channel-adapted error correction maximizes fidelity.

Such methods are more robust to channel changes.

Results are supported by numerical evidence.

Abstract

A quantum channel models the interaction between the system we are interested in and its environment. Such a model can capture the main features of the interaction but because of the complexity of the environment we can not assume that it is fully accurate. We study the robustness of quantum error correction operations against completely unexpected and subsequently undetermined type of channel uncertainties. We find that a channel-adapted optimal error correction operation does not only give the best possible channel fidelity but it is more robust against channel alterations than any other error correction operation. Our results are valid for Pauli channels and stabilizer codes but based on some numerical results we believe that very similar conclusions can be drawn also in the general case.