Observing information backflow from controllable non-Markovian multi-channels in diamond

TL;DR

This paper demonstrates the experimental control of non-Markovian quantum dynamics in diamond, showing how information flows between a quantum system and its environment through multiple engineered channels, advancing quantum metrology and open system understanding.

Contribution

It introduces a method to engineer and control multiple dissipative channels in a diamond NV center, enabling the study of non-Markovian information backflow in quantum systems.

Findings

Controlled non-Markovian dynamics observed

Quantum Fisher information flows to and from environment

Enhanced understanding of quantum open systems

Abstract

Any realistic quantum system is inevitably subject to an external environment. This environment makes the open-system dynamics significant for many quantum tech-nologies, such as entangled-state engineering, quantum simulation, and quantum sensing. The information flow of a system to its environment usually induces a Markovian process, while the backflow of information from the environment exhibits non-Markovianity. The practical environment, usually consisting of a large number of degrees of freedom, is hard to control, despite some attempts on controllable transitions from Markovian to non-Markovian dynamics. Here, we experimentally demonstrate the engineering of multiple dissipative channels by controlling the adjacent nuclear spins of a nitrogen-vacancy centre in diamond. With a controllable non-Markovian dynamics of the open system, we observe that the quantum Fisher information flows to and from the environment using different noisy channels. Our work contributes to the developments of both noisy quantum metrology and quantum open systems from the view points of metrologically useful entanglement.