Non-Markovian disentanglement dynamics of two-qubit system

TL;DR

This paper studies how entanglement between two qubits decays over time in non-Markovian environments, revealing conditions for exponential decay and sudden death based on coupling strength.

Contribution

It provides new insights into the disentanglement dynamics of two-qubit systems in non-Markovian settings, highlighting the impact of coupling strength on entanglement decay behavior.

Findings

Entanglement decays exponentially when coupling is near or below 1/137.

Strong coupling leads to sudden death of entanglement.

Vacuum environment does not prevent entanglement sudden death at high coupling.

Abstract

We investigated the disentanglement dynamics of two-qubit system in Non-Markovian approach. We showed that only the couple strength with the environment near to or less than fine-structure constant 1/137, entanglement appear exponential decay for a certain class of two-qubit entangled state. While the coupling between qubit and the environment is much larger, system always appears the sudden-death of entanglement even in the vacuum environment.