Mixed-state certification of quantum capacities for noisy communication channels

TL;DR

This paper develops a method to certify the quantum capacity of noisy communication channels using realistic input states and measurement procedures, providing a new bound for the coherent information applicable in practical scenarios.

Contribution

It introduces a generalized approach for lower bounding quantum capacity with mixed inputs and arbitrary measurements, extending previous methods to more realistic settings.

Findings

New bound for the coherent information applicable to mixed states

Enhanced certification method for quantum capacities in noisy channels

Applicable to general input states and output measurements

Abstract

We extend a recent method to detect lower bounds to the quantum capacity of quantum communication channels by considering realistic scenarios with general input probe states and arbitrary detection procedures at the output. Realistic certification relies on a new bound for the coherent information of a quantum channel that can be applied with arbitrary bipartite mixed input states and generalized output measurements.