Reconstructing Non-Markovian Open Quantum Evolution From Multi-time Measurements

TL;DR

This paper introduces a tomography algorithm that reconstructs the minimal environment and the non-Markovian quantum evolution of a system from multi-time measurements, enabling accurate future predictions.

Contribution

It presents a novel method to reconstruct the environment and dynamics of non-Markovian quantum systems using multi-time measurement data.

Findings

Successfully reconstructs minimal environment for non-Markovian dynamics

Enables prediction of future system behavior under time-independent assumptions

Defines measures of memory size and complexity for quantum evolution

Abstract

For a quantum system undergoing non-Markovian open quantum dynamics, we demonstrate a tomography algorithm based on multi-time measurements of the system, which reconstructs a minimal environment coupled to the system, such that the system plus environment undergoes unitary evolution and that the reduced dynamics of the system is identical to the observed dynamics of it. The reconstructed open quantum evolution model can be used to predict any future dynamics of the system when it is further assumed to be time-independent. We define the memory size and memory complexity for the non-Markovian open quantum dynamics which characterize the complexity of the reconstruction.