Exploring classical correlations in noise to recover quantum information using local filtering

TL;DR

This paper investigates how local filtering can recover quantum information lost due to noise in quantum channels, highlighting differences between types of noise and proposing optimal recovery schemes.

Contribution

It introduces a method to restore quantum correlations in noisy channels using local filtering, with analysis of different noise types and strategies for maximal information recovery.

Findings

Local filtering can significantly restore quantum correlations.

Bit-flip and phase-flip noise affect recovery differently.

A scheme for optimal quantum information recovery is proposed.

Abstract

A general quantum channel consisting of a decohering and a filtering element carries one qubit of an entangled photon pair. As we apply a local filter to the other qubit, some mutual quantum information between the two qubits is restored depending on the properties of the noise mixed into the signal. We demonstrate a drastic difference between channels with bit-flip and phase-flip noise and further suggest a scheme for maximal recovery of the quantum information.