Contraction coefficients for noisy quantum channels

TL;DR

This paper investigates how various measures of quantum information, such as relative entropy and trace distance, contract under noisy quantum channels, providing new bounds and relationships between their maximal contractions.

Contribution

It introduces novel bounds and relationships for the maximal contraction of quantum information measures under noisy quantum channels.

Findings

Derived new bounds on contraction coefficients.

Established relationships between different quantum information measures.

Enhanced understanding of quantum channel effects on information measures.

Abstract

Generalized relative entropy, monotone Riemannian metrics, geodesic distance, and trace distance are all known to decrease under the action of quantum channels. We give some new bounds on, and relationships between, the maximal contraction for these quantities.