  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.
