Distinguishing environment-induced non-Markovianity from subsystem dynamics

TL;DR

This paper introduces a spectral method to differentiate between environment-induced and subsystem interaction-induced non-Markovian effects in quantum systems, demonstrated on a qubit model with various noise channels.

Contribution

It presents a novel power spectrum technique to identify multiple sources of non-Markovianity in complex quantum systems, advancing understanding of decoherence processes.

Findings

Effective distinction between different non-Markovian sources

Application to a qubit system with Jaynes-Cummings interaction

Analysis of noise channels like telegraph noise and amplitude damping

Abstract

Quantum non-Markovianity modifies the environmental decoherence of a system. This situation is enriched in complex systems owing to interactions among subsystems. We consider the problem of distinguishing the multiple sources of non-Markovianity using a simple power spectrum technique, applied to a qubit interacting with another qubit via a Jaynes-Cummings type Hamiltonian and simultaneously subjected to some well known noise channels, such as, the random telegraph noise and non-Markovian amplitude damping, which exhibit both Markovian as well as non-Markovian dynamics under different parameter ranges.