The Hidden Nature of Non-Markovianity

TL;DR

This paper explores the nature of non-Markovian quantum dynamics, revealing that non-Markovian effects are hidden when analyzing individual trajectories, as they can be replicated by time-dependent Markovian processes.

Contribution

It demonstrates that non-Markovian quantum evolutions can be mimicked by time-dependent Lindbladians, making non-Markovianity invisible at the trajectory level.

Findings

Non-Markovian trajectories can be generated from time-dependent Lindbladians.

Non-Markovian effects are not observable in single trajectories.

Every trajectory under mild assumptions can be reproduced by a family of time-dependent Lindbladians.

Abstract

The theory of open quantum systems served as a tool to prepare entanglement at the beginning stage of quantum technology and more recently provides an important tool for state preparation. Dynamics given by time dependent Lindbladians are Markovian and lead to decoherence, decay of correlation and convergence to equilibrium. In contrast Non-Markovian evolutions can outperform their Markovian counterparts by enhancing memory. In this letter we compare the trajectories of Markovian and Non-Markovian evolutions starting from a fixed initial value. It turns out that under mild assumptions every trajectory can be obtained from a family of time dependent Lindbladians. Hence Non-Markovianity is invisible if single trajectories are concerned.