Quantum correlations of three-qubit states driven by a classical random external field

Abstract

In this paper, we exploit the notions of tripartite quantum discord  (3) , tripartite negativity  (3) , and entanglement witnesses (EWs), respectively, as a measure of quantum correlations in a model of three noninteracting qubits subject to a classical random external field. We compare the dynamics of  (3) with that of entanglement for the initial entangled pure or mixed GHZ-and W-type states. We find that the quantum correlations dynamics depend on the input configuration of the purity of the initial states. The results show that  (3) may be more robust than entanglement and no sudden death of the  (3) occurs, whereas entanglement displays periodically sudden death and revivals in the regions for GHZ-and W-type states driven by a classical random external field. Furthermore, we also show that the survival partial entanglement can be detected by means of the suitable EWs.

Quantum Fisher information of two atoms with dipole–dipole interaction under the environment of phase noise lasers

“…And their decay will be independent decay. This case can be solved analytically, as we and other authors have done before 1 , 32 – 34 .…”

“…In 2010, based on Agarwal’s PNLs model 20 , 21 , 25 , 30 , and by using the Zwanzig–Nakajima projection operator technique, J.D.Cresser derived a master equation without a stochastic variable 31 . After that, there are some researchers studied the physical problems on PNLs with this J.D.Cresser’s master equation, such as QFI 1 , 32 , the discord of two-qubit X state 33 , and the discord and the entanglement of three-qubit GHZ state and W state 34 . Although they investigated multi-atom PNLs problems by using this master equation, their calculations are with no interactions between atoms and no spontaneous emissions, and do not focus on more complicated problems with d – d interactions and collective decay (or cooperative emission) of multiple atoms when the atoms are much closer to each other.…”

Effects of classical random external field on the dynamics of entanglement in a four-qubit system

“…where I i jk represents the identity matrix acting on the Hilbert space of the qubits i, j and k and ℋ s , s = a, b, c, d stands for the single qubit-field Hamiltonian which can be written in the rotating frame at the qubit-field resonant frequency ω as [24,28] ℋ s (t) = i hg σ + e −iφ s i − σ − e iφ s i .…”

“…They also showed that in such an environment, quantum correlations do not vanish any more when the probabilities of the field phase range from 0.5 to 1 (the behavior is symmetric with respect to 0.5). Furthermore, in 2015 the dynamic of quantum correlations of three-qubit states driven by a CREF has been studied by Guo et al [28] and their results show that tripartite quantum discord may be more robust than entanglement under such a classical environment. They also showed that under this classical field, entanglement displays periodically sudden death and revivals for GHZ-and W-type states and that the survival partial entanglement can be detected employing suitable entanglement witness operators.…”

“…They also showed that under this classical field, entanglement displays periodically sudden death and revivals for GHZ-and W-type states and that the survival partial entanglement can be detected employing suitable entanglement witness operators. [28] In 2016, other authors addressed the sudden death and rebirth of entanglement for different dimensional systems driven by CREF. [29] They perceived that entanglement behaviors present decay, sudden death, sudden birth, and long-lived in some period.…”