Linear response of tripartite entanglement to infinitesimal noise

TL;DR

This paper investigates how tripartite entanglement in three-qubit systems responds to infinitesimal noise, revealing that bipartite entanglement accelerates the decay of tripartite entanglement during initial decoherence.

Contribution

It introduces a family of global noise models and derives a lower bound for the linear response of tripartite entanglement in symmetric three-qubit states.

Findings

Lower bound of linear response depends on initial tripartite and bipartite entanglement

Bipartite entanglement accelerates tripartite entanglement decay

Response analyzed under a specific family of global noise involving four W states

Abstract

Recent experimental progress in prolonging the coherence time of a quantum system prompts us to explore the behavior of quantum entanglement at the beginning of the decoherence process. The response of the entanglement under an infinitesimal noise can serve as a signature of the robustness of entangled states. A crucial problem of this topic in multipartite systems is to compute the degree of entanglement in a mixed state. We find a family of global noise in three-qubit systems, which is composed of four W states. Under its influence, the linear response of the tripartite entanglement of a symmetrical three-qubit pure state is studied. A lower bound of the linear response is found to depend completely on the initial tripartite and bipartite entanglement. This result shows that the decay of tripartite entanglement is hastened by the bipartite one.