Multipartite entanglement and purity dynamics in classical channels influenced by fractional Gaussian noise

TL;DR

This paper studies how fractional Gaussian noise influences entanglement and purity in four-qubit GHZ states within classical channels, revealing conditions for preserving quantum correlations and the impact of noise characteristics.

Contribution

It introduces a detailed analysis of multipartite entanglement dynamics under fractional Gaussian noise, highlighting the role of the Hurst parameter in preserving quantum correlations.

Findings

Indefinite entanglement and purity can be simulated in multipartite GHZ states.

Entanglement and purity decrease exponentially with noise, with revivals suppressed.

The Hurst parameter improves entanglement preservation and reduces mixedness.

Abstract

The dynamical map of entanglement and mixedness in four-qubit maximally entangled GHZ state paired with classical channels driven by fractional Gaussian noise is investigated. The qubit-channel coupling is assumed in four distinct ways: common, bipartite, tripartite, and independent local channel-qubit configurations comprising single, double, triple, or independent noisy sources. Using entanglement witness, negativity, purity and von Neumann entropy, except for the independent configuration, we show that indefinite entanglement and purity preservation may be simulated in multipartite GHZ-like states. Quantum correlations and purity decrease exponentially in four qubits, and exact fluctuating local field behaviour, as well as entanglement sudden death and birth revivals, are completely suppressed. Entanglement and purity preservation are affected by noise and the number of independent channels utilised. The Hurst parameter of fractional Gaussian noise was discovered in the four qubits to improve entanglement and avoid mixedness. Different entanglement and mixedness criteria yield different results, emphasizing the need to investigate various approaches in order to uncover multipartite correlations.