Classification and purification for the independent quantum channel through quantum error-correction

TL;DR

This paper demonstrates how quantum error-correction can classify independent quantum channels into five types and purify four of them, revealing that channel purity, not fidelity, determines quantum state preservation.

Contribution

It introduces a novel classification and purification method for independent quantum channels using quantum error-correction, emphasizing the role of channel purity over fidelity.

Findings

Quantum error-correction classifies channels into 5 types.

Four types of channels can be purified.

Channel purity, not fidelity, affects quantum state preservation.

Abstract

The essence of quantum error-correction is to use redundant Hilbert space to identify and correct errors, and the channel fidelity of the quantum channel does not affect which errors can be identified and corrected. Based on this, it is found that quantum error-correction can be used to classify the independent quantum channel into 5 types, and 4 of the 5 types can be purified. It is found in quantum error-correction, the decoherence of quantum state may be related to the degree of identification for the state under quantum noise, and the results of this work confirmed that the degree of purity of quantum channel determines its ability to retain the quantum property of the quantum state, not the fidelity. In this work, the identification of the independent Pauli channels by quantum error-correction is demonstrated.