Dephasing-Induced Distribution of Entanglement in Tripartite Quantum Systems

TL;DR

This paper investigates how multipartite entanglement distribution in tripartite quantum systems is affected by dephasing and decoherence, using a novel entanglement quantifier based on relative entropy, under various environmental interactions.

Contribution

It introduces a new entanglement distribution measure applicable to mixed states and analyzes its behavior under different dephasing and bath configurations.

Findings

Entanglement robustness depends on distribution and bath interaction.

Shared environment affects entanglement dynamics differently than local environments.

Mixed states show unique robustness in common reservoir scenarios.

Abstract

Preserving multipartite entanglement amidst decoherence poses a pivotal challenge in quantum information processing. However, assessing multipartite entanglement in mixed states amid decoherence presenting a formidable task. Employing reservoir memory offers a means to attenuate the decoherence dynamics impacting multipartite entanglement, thereby slowing its degradation. One of the important measures which can be implemented to quantify entanglement is the relative entropy of entanglement. Although this measure is not monogamous \cite{horodeckirev2009}, it can universally be applied to both pure and mixed states. Based on this fundamental novelty, in this work, therefore, we introduce a quantifier which will investigate how entanglement remain distributed among the qubits of multipartite states when these states are exposed to multipartite dephasing setting. For our study we use various pure and mixed tripartite states subjected to finite temperature in both Markovian and non-Markovian local/common bath. Here, we consider situations where the three qubits interact with a common reservoir as well as a local bosonic reservoir. We also show that the robustness of a quantum system to decoherence depends on the distribution of entanglement and its interaction with various configurations of the bath. When each qubit has its own local environment, the system exhibits different distribution dynamics compared to when all three qubits share a common environment with one exception regarding a mixed state.