Measuring and using non-markovianity

TL;DR

This paper introduces new measures for quantifying non-Markovianity in quantum processes, linking it to information screening and resource potential, with analysis of key quantum models.

Contribution

It proposes physically meaningful measures based on channel capacity revivals, improving upon existing non-Markovianity quantifiers.

Findings

Measures relate non-Markovianity to information screening.

Non-Markovianity can serve as a quantum resource.

Application to Jaynes-Cummings model and qubit environments.

Abstract

We construct measures for the non-Markovianity of quantum evolution with a physically meaningful interpretation. We first provide a general setting in the framework of channel capacities and propose two families of meaningful quantitative measures, based on the largest revival of a channel capacity, avoiding some drawbacks of other non-Markovianity measures. We relate the proposed measures to the task of information screening. This shows that the non-Markovianity of a quantum process may be used as a resource. Under these considerations, we analyze two paradigmatic examples, a qubit in a quantum environment with classically mixed dynamics and the Jaynes-Cummings model.