Global correlation and local information flows in controllable non-Markovian open quantum dynamics

• Published in: npj quantum information Vol. 8; no. 1; pp. 1 - 6
• Main Authors: Chen, Xin-Yu, Zhang, Na-Na, He, Wan-Ting, Kong, Xiang-Yu, Tao, Ming-Jie, Deng, Fu-Guo, Ai, Qing, Long, Gui-Lu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.03.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/400/482; 639/766/483/1139; 639/766/483/3926; 639/766/483/481; Classical and Quantum Gravitation; Physics; Physics and Astronomy; Quantum Computing; Quantum Field Theories; Quantum Information Technology; Quantum Physics; Quantum theory; Relativity Theory; Spintronics; String Theory
• ISSN: 2056-6387; 2056-6387
• DOI: 10.1038/s41534-022-00537-z

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.