Time evolution of tripartite quantum discord and entanglement under local and nonlocal random telegraph noise

Abstract

Few studies explored the dynamics of nonclassical correlations besides entanglement in open multipartite\ud quantum systems. Here, we address the time evolution of quantum discord and entanglement in a model of\ud three noninteracting qubits subject to a classical random telegraph noise in common and separated environments.\ud Two initial entangled states of the system are examined, namely the GHZ- and W-type states. The dynamics\ud of quantum correlations results to be strongly affected by the input configuration of the qubits, the type of the\ud system-environment interaction, and the memory properties of the environmental noise. When the qubits are\ud nonlocally coupled to the random telegraph noise, the GHZ-type states partially preserve, at long times, both\ud discord and entanglement, regardless of the correlation time of the environmental noise. The survived entangled\ud states turn out to be also detectable by means of suitable entanglement witnesses. On the other hand, in the same\ud conditions, the decohering effects suppress all the quantum correlation of the W-type states which are thus less\ud robust than the GHZ-type ones. The long-time survival of tripartite discord and entanglement opens interesting\ud perspectives in the use of multipartite entangled states for practical applications in quantum information science

Dynamics of entanglement and state-space trajectories followed by a system of four-qubit in the presence of random telegraph noise: common environment (CE) versus independent environments (IEs)

“…Where N  is an N×N identity matrix. As expected according to the definition of an entanglement witness operator given above, negative expectation values of the entanglement witnesses GHZ N  ( ) and W N  ( ) indicate the appearance of multi-qubit entanglement experimentally detectable in the system meanwhile zero or positive expectation values do not guarantee the absence of entanglement [58].…”

“…For instance, it has been found that for multi-qubit systems, the degree of entanglement robustness tends to increases or decreases with the increase of the number of qubits of the system [8,56]. In particular, the dynamics of quantum correlations in terms of entanglement and discord in a physical model of three non-interacting qubits subject to a classical environmental noise has recently been investigated [57][58][59]. In the present work, in order to have an insight on how the entanglement behaves in the model studied in the above mentioned works (that is, [57][58][59]) when the number of qubits is increased, we extend this model from three to four qubits.…”

“…In particular, the dynamics of quantum correlations in terms of entanglement and discord in a physical model of three non-interacting qubits subject to a classical environmental noise has recently been investigated [57][58][59]. In the present work, in order to have an insight on how the entanglement behaves in the model studied in the above mentioned works (that is, [57][58][59]) when the number of qubits is increased, we extend this model from three to four qubits. Stated another way, the main purpose of this work is to explore whether the increasing of the number of qubits in such a model leads to the increase or decrease of the entanglement fragility.…”

Quantum correlations of identical particles subject to classical environmental noise

“…This system is the bosonic version of the Hubbard plaquette, which is used in solid state as a building block for highly correlated manybody systems [108][109][110][111]. In agreement with previous works [61,66,67,90], in order to mimic the effect of the noise on the quantum system the hopping amplitudes among the sites are assumed to follow a time-dependent stochastic behavior. Such an assumption yields the Hamiltonian [27,40] …”

Dissociation and annihilation of multipartite entanglement structure in dissipative quantum dynamics

“…Campbell et al used fidelity-and collective-spin-based entanglement witnesses to analyze the dynamics of genuine multipartite entanglement of Dicke states under local amplitude-damping, phase-damping, and depolarizing channels [46]. Tripartite negativity and generalized concurrence were also applied to the dissipative dynamics of GHZ and W three-qubit entangled states [47][48][49][50][51][52]. Let us recall that the above measures are not precise, i.e., their zero values do not imply in general that the genuine entanglement is lost.…”