Entanglement evolution of three-qubit mixed states in multipartite cavity—reservoir systems

Abstract

We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is shown that the entanglement evolution is restricted by a set of monogamy relations. Furthermore, as quantified by the negativity, the entanglement dynamical property of the mixed entangled state of cavity photons is investigated. It is found that the three cavity photons can exhibit the phenomenon of entanglement sudden death (ESD). However, compared with the evolution of a generalized three-qubit GHZ state which has the equal initial entanglement, the ESD time of mixed states is later than that of the pure state. Finally, we discuss the entanglement distribution in the multipartite system, and point out the intrinsic relation between the ESD of cavity photons and the entanglement sudden birth of reservoirs.

Preserving entanglement and the fidelity of three-qubit quantum states undergoing decoherence using weak measurement

“…On the other hand, as shown in Eqs. (12) and (20), under the same decoherence and fidelity protection protocol, the GHZ state and W state, which have equal fidelity initially, may evolve into inequivalent states containing unequal fidelity. For the two cases, when the optimal reversing measurement strength p r = p + D(1 − p) is chosen, the difference of the fidelity of the final states is given as…”

“…For a multipartite quantum system, decoherence often results in degradation of entanglement and, in certain cases, entanglement sudden death (ESD). Therefore, understanding entanglement dynamics [11][12][13][14][15][16][17][18][19][20][21] and designing strategies [22][23][24][25][26][27][28][29][30][31][32] to manipulate entanglement become a long-term pursuit in the field of entanglement-based quantum information technology.…”

Promote entanglement trapping in photonic band gaps

“…Entanglement is a fundamental resource of quantum information, especially the bipartite entanglement between remote parties, which is useful to realize quantum teleportation, [1] quantum key distribution, [2,3] quantum computing, [4,5] and so on. In reality, entanglement is quite fragile in the presence of decoherence [6][7][8] due to the fact that no system can be completely isolated. Therefore, the control and the protection of entanglement from decoherence become one of the crucial issues in quantum optics and quantum information science.…”

Relation between initial conditions and entanglement sudden death for two-qubit extended Werner-like states

“…On the one hand, existence of ESD has been extensively demonstrated. ESD of a system, which consists of interacting [14][15][16] or non-interacting [17][18][19] entangled partners and is disturbed by common [20][21][22] or independent [23][24][25][26] amplitude damping noise, [10,27] phase damping noise, [28,29] or others, [30] has been found. On the other hand, it is important to avoid ESD in practice so that quantum information processing and quantum computation tasks based on entanglement can be successfully accomplished.…”