Entanglement and non-Markovianity of quantum evolutions

TL;DR

This paper introduces two practical measures for quantifying the non-Markovian nature of quantum evolutions, applicable in different experimental scenarios, without requiring complex optimization procedures.

Contribution

The authors propose two novel, experimentally accessible measures of quantum non-Markovianity, one necessary and sufficient with full information, and one sufficient with no information, avoiding optimization.

Findings

Measures effectively distinguish Markovian and non-Markovian dynamics.

Criteria are practical and do not rely on optimization procedures.

Applicable in diverse experimental contexts.

Abstract

We address the problem of quantifying the non-Markovian character of quantum time-evolutions of general systems in contact with an environment. We introduce two different measures of non-Markovianity that exploit the specific traits of quantum correlations and are suitable for opposite experimental contexts. When complete tomographic knowledge about the evolution is available, our measure provides a necessary and sufficient condition to quantify strictly the non-Markovianity. In the opposite case, when no information whatsoever is available, we propose a sufficient condition for non-Markovianity. Remarkably, no optimization procedure underlies our derivation, which greatly enhances the practical relevance of the proposed criteria.