Global Correlation and Local Information Flows in Controllable Non-Markovian Open Quantum Dynamics

TL;DR

This paper investigates non-Markovian open quantum dynamics using global and local measures, demonstrating how quantum mutual information and quantum Fisher information flow can characterize non-Markovianity in controllable experiments.

Contribution

It introduces a combined approach using QMI and QFI flow to effectively measure non-Markovianity in multi-channel quantum processes, advancing understanding of quantum information flow.

Findings

Transition from Markovian to non-Markovian dynamics by tuning base frequency.

QMI decays monotonically in Markovian processes, but can rise in non-Markovian ones.

QMI and QFI flow together effectively characterize non-Markovianity.

Abstract

In a fully-controllable experiment platform for studying non-Markovian open quantum dynamics, we show that the non-Markovianity could be investigated from the global and local aspects. By mixing random unitary dynamics, we demonstrate non-Markovian and Markovian open quantum dynamics. From the global point of view, by tuning the base frequency we demonstrate the transition from the Markovianity to the non-Markovianity as measured by the quantum mutual information (QMI). In a Markovian open quantum process, the QMI decays monotonically, while it may rise temporarily in a non-Markovian process. However, under some circumstances, it is not sufficient to globally investigate the non-Markovianity of the open quantum dynamics. As an essential supplement, we further utilize the quantum Fisher information (QFI) flow to locally characterize the non-Markovianity in different channels. We demonstrate that the QMI in combination with the QFI flow are capable of measuring the non-Markovianity for a multi-channel open quantum dynamics.