Quantum Error-Correcting Codes Need Not Completely Reveal the Error Syndrome

TL;DR

This paper introduces a quantum error-correcting code that does not require revealing the complete error syndrome, enabling reliable quantum communication over noisier channels than previously possible.

Contribution

The authors propose a novel quantum error-correcting code that tolerates higher noise levels by not fully revealing the error syndrome, improving robustness over existing codes.

Findings

Code achieves fidelity of 0.8096 on depolarizing channel

Outperforms previous code with fidelity of 0.8107

Enables reliable quantum communication with more than one bit of entropy per qubit

Abstract

Quantum error-correcting codes so far proposed have not worked in the presence of noise which introduces more than one bit of entropy per qubit sent through a quantum channel, nor can any code which identifies the complete error syndrome. We describe a code which does not find the complete error syndrome and can be used for reliable transmission of quantum information through channels which add more than one bit of entropy per transmitted bit. In the case of the depolarizing channel our code can be used in a channel of fidelity .8096. The best existing code worked only down to .8107.