Measure for the Non-Markovianity of Quantum Processes

TL;DR

This paper discusses a measure for non-Markovian behavior in quantum processes based on information flow, providing mathematical details, applications, and implications for quantum systems.

Contribution

It elaborates the mathematical foundation of an information flow-based measure for quantum non-Markovianity and explores its applications and relations to other approaches.

Findings

The measure quantifies information backflow in quantum processes.

Applications to physical models demonstrate the measure's effectiveness.

Discussion of experimental implications and alternative approaches.

Abstract

Recently, a measure for the non-Markovian behavior of quantum processes in open systems has been developed which is based on the quantification of the flow of information between the open system and its environment [Phys. Rev. Lett. 103, 210401 (2009)]. The information flow is connected to the rate of change of the trace distance between quantum states which can be interpreted in terms of the distinguishability of these states. Here, we elaborate the mathematical details of this theory, present applications to specific physical models, and discuss further theoretical and experimental implications, as well as relations to alternative approaches proposed recently.