In a fully-controllable experiment platform for studying non-Markovian open quantum dynamics, researchers have showed that the non-Markovianity could be investigated from the global and local aspects.
By mixing random unitary dynamics, they demonstrated non-Markovian and Markovian open quantum dynamics. From the global point of view, by tuning the base frequency they demonstrated 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, they further utilized the Quantum Fisher Information (QFI) flow to locally characterize the non-Markovianity in different channels.
The team demonstrated that the QMI in combination with the QFI flow are capable of measuring the non-Markovianity for a multi-channel open quantum dynamics.
npj Quantum Information, Published online: 03 March 2022; doi:10.1038/s41534-022-00537-z
