Tripartite quantum discord dynamics in qubits driven by the joint influence of distinct classical noises

Abstract

We investigate the dynamics of quantum discord in a system of three non-interacting qubits, initially entangled in a Greenberger–Horne–Zeilinger state, in the presence of mixed classical environments. Precisely, the joint impacts of a static noise (SN) and a random telegraphic noise (RTN) are probed, by combining them in two different ways: independent and bipartite system–environment coupling. For both cases, one marginal system is coupled with an environment (say $$E_1$$ ), and the remaining subsystems are coupled either locally or not with a second environment ( $$E_2$$ ), and vice versa. We show that quantum discord is more fragile in independent environments than in bipartite ones no matter the Markovianity of the dynamical process, and may exhibit sudden death and revival phenomena. A static noise is more fatal to the survival of quantum discord than a RTN, and its shielding effects are more pronounced as the number of subsystems under its effects increases. The opposite is found for a RTN, where discord robustness is enhanced as the number of affected subsystems increases.