An alternative non-Markovianity measure by divisibility of dynamical map

TL;DR

This paper introduces a new non-Markovianity measure for quantum processes based on divisibility of the dynamical map, which is practical, optimization-free, and applicable to all quantum processes.

Contribution

It proposes a novel non-Markovianity measure based on divisibility, avoiding optimization and applicable to any quantum process, with comparisons to existing measures.

Findings

The measure effectively identifies non-Markovian quantum processes.

It is finite and does not require optimization.

Examples demonstrate the measure's practical utility.

Abstract

Identifying non-Markovianity with non-divisibility, we propose a measure for non-Markovinity of quantum process. Three examples are presented to illustrate the non-Markovianity, measure for non-Markovianity is calculated and discussed. Comparison with other measures of non-Markovianity is made. Our non-Markovianity measure has the merit that no optimization procedure is required and it is finite for any quantum process, which greatly enhances the practical relevance of the proposed measure.