arXiv:1406.5767 · Physical Review A

Sudden change in dynamics of genuine multipartite entanglement of cavity-reservoir qubits

Mazhar Ali, A. R. P. Rau

Published Oct 23, 2014• 18 citations

Abstract

We study the dynamics of genuine multipartite entanglement for a system of four qubits. Using a computable entanglement monotone for multipartite systems, we investigate the as yet unexplored aspects of a cavity-reservoir system of qubits. For one specific initial state, we observe a sudden transition in the dynamics of genuine entanglement for the four qubits. This sudden change occurs only during a time window where neither cavity-cavity qubits nor reservoir-reservoir qubits are entangled. We show that the sudden change in dynamics of this specific state is extremely sensitive to white noise.

DOI: 10.1103/physreva.90.042330

Related papers

Sudden change of genuine multipartite entanglement in non-Markovian dynamics

Mazhar Ali

We investigate entanglement dynamics of bipartite as well multipartite systems beyond Markov approximation. We study two pairs of cavity–reservoir systems, modeled as four qubits and track the change of entanglement among cavity–cavity qubits, reservoir–reservoir qubits, and also for genuine entanglement of all four qubits. For cavity–cavity qubits, we find that non-Markovianity prolongs the life of entanglement besides collapse/revival phenomenon. For reservoir–reservoir qubits, entanglement sudden birth is delayed accordingly along with oscillations. For all four qubits, with a specific initial state, we find that genuine entanglement develops gradually, reaches to a maximum constant value and then freezes at this value for some time before decaying. This sudden change in dynamics of genuine entanglement occurs for a time window where neither cavities nor reservoirs are entangled. In contrast to Markov process, sudden change phenomenon may be recurrent in non-Markovian regime.

arXiv:2405.13412Canadian Journal of PhysicsJun 4, 20240 citations

Freezing dynamics of genuine entanglement and loss of genuine nonlocality under collective dephasing

Mazhar Ali

We study the dynamics of genuine multipartite entanglement for quantum systems upto four qubits interacting with general collective dephasing process. Using a computable entanglement monotone for multipartite systems, we observe the feature of freezing dynamics of genuine entanglement for three and four qubits entangled states. We compare the dynamics with that of random states and find that most states exibit this feature. We then study the effects of collective dephasing on genuine nonlocality and find out that although quantum states remain genuinely entangled yet their genuine nonlocality is lost in a finite time. We show the sensitivity of asymptotic states being genuinely entangled by mixing white noise.

arXiv:1703.09932International Journal of Quantum InformationApr 1, 20173 citations

Decoherence of genuine multipartite entanglement for local non-Markovian–Lorentzian reservoirs

Mazhar Ali

We study decoherence effects on genuine multipartite entanglement for three and four qubits, spatially separated and subjected to local Lorentzian reservoirs. Employing recent techniques to compute genuine negativity for multipartite systems and an exact solvable model, we analyze the dynamics of genuine entanglement for different coupling bandwidths and detunings. We find that collapses and revivals can occur by varying these parameters for various multipartite quantum states.

Chinese Physics BDec 1, 20155 citations

Entanglement monogamy and entanglement evolution in multipartite systems

Yan-Kui Bai, Ming-Yong Ye, Z. D. Wang

We analyze the entanglement distribution and the two-qubit residual entanglement in multipartite systems. For a composite system consisting of two cavities interacting with independent reservoirs, it is revealed that the entanglement evolution is restricted by an entanglement monogamy relation derived here. Moreover, it is found that the initial cavity-cavity entanglement evolves completely to the genuine four-partite cavities-reservoirs entanglement in the time interval between the sudden death of cavity-cavity entanglement and the birth of reservoir-reservoir entanglement. In addition, we also address the relationship between the genuine block-block entanglement form and qubit-block form in the interval.

arXiv:0906.0430Physical Review AOct 15, 200986 citations

Dynamics of genuine multipartite entanglement in a quantum spin system

Jiang Zhou, Hong Mei Guo

The time evolution of genuine multipartite entanglement is numerically studied in a model many-spin system decohered by a structured spin bath. It is found that multipartite entanglement can be more persistent than the bipartite entanglement and can even evolve into a specific constant under certain conditions. Besides, multipartite entanglement sudden death and sudden birth are observed. It is shown that the randomness of the coupling strength and connectivity between the spins in the environment will suppress these birth and death phenomena. Furthermore, the initial state of the central system plays a significant role in determining multipartite entanglement dynamics.

Journal of Physics B Atomic Molecular and Optical PhysicsNov 2, 20122 citations

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

Jingzhou Xu, Jinbao Guo, Wen, Wei +2 more

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.

Jan 1, 20127 citations