Witnessing quantum capacities of correlated channels

TL;DR

This paper presents a practical method to estimate lower bounds of quantum channel capacities for correlated two-qubit channels, avoiding complex tomography and requiring no prior channel knowledge.

Contribution

It introduces an efficient, implementable approach to detect quantum capacities of correlated channels without full process tomography or prior information.

Findings

Method effectively detects lower bounds of quantum capacity.

Applicable to correlated dephasing, depolarising, and amplitude damping channels.

Does not require full quantum process tomography.

Abstract

We test a general method to detect lower bounds of the quantum channel capacity for two-qubit correlated channels. We consider in particular correlated dephasing, depolarising and amplitude damping channels. We show that the method is easily implementable, it does not require a priori knowledge about the channels, and it is very efficient, since it does not rely on full quantum process tomography.