Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Chinese Physics Letters

Quantum Discord Dynamics in Two Different Non-Markovian Reservoirs

Bang-Fu Ding, Xiao-Yun Wang, Jing-Feng Liu, Lin Yan, Heping Zhao

Published Oct 1, 2011• 8 citations
Publisher

Abstract

The quantum discord dynamics of two non-coupled two-level atoms independently interacting with their reservoir is studied under two kinds of non-Markovian conditions, namely, an off-resonant case with atomic transition frequency and a photonic band gap. In the first case, the phenomenon of the quantum discord loss and the oscillatory behavior of the quantum discord can occur by changing the detuning quantity and reducing the spectral coupling width for any initial Bell state. Under the second condition, the trapping phenomenon of the quantum discord can be presented by adjusting the width of gap, that is, the quantum discord of two atoms keep a nonzero constant for a long time.

DOI
10.1088/0256-307x/28/10/104216

Related papers

Non-Markovian dynamics of two non-coupled qubits interacting with two separate reservoirs with different spectral densities

Xiao-Yun Wang, Bang-Fu Ding, Heping Zhao

The dynamics of two non-coupled qubits independently interacting with their reservoirs is solved by the time convolutionless projection operator method. We study two-qubit quantum correlation dynamics for two different types of spectral densities, which are a Lorentzian distribution and an Ohmic spectral density with a Lorentzian—Drude cutoff function. For two qubits initially prepared in the initial Bell state, quantum discord can keep longer time and reach larger values in non-Markovian reservoirs for the first spectral distribution or by reducing the cutoff frequency for the second case. For the initial Bell-like state, the dynamic behaviors of quantum discord and entanglement are compared. The results show that a long time of quantum correlation can be obtained by adjusting some parameters in experiment and further confirm that the discord can capture quantum correlation in addition to entanglement.

Chinese Physics B•Apr 1, 2013•7 citations

Quantum Discord Dynamics of Three Qubits in Non-Markovian Environments

Yan Zhang, Jin‐Ming Liu, Yan-Jie Li

We investigate the dynamics of pairwise quantum discord (QD) for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lorentzian spectral density. The influence of the environment's amount of non-Markovianity, the detuning between the qubit frequency and the cavity centre frequency, and the purity of the initial state on the QD dynamics are analyzed in detail. It is found that in the non-Markovian regime the system-reservoir interactions induce QD revivals and oscillations no matter whether the detuning is zero or not. Moreover, QD can be preserved for a long time if the non-Markovian condition and the detuning condition are satisfied simultaneously.

Communications in Theoretical Physics•Jun 1, 2014•8 citations

Quantum correlation dynamics of three non-coupled two-level atoms in different reservoirs

Xiao-Yun Wang, Bang-Fu Ding, Heping Zhao

Time evolution dynamics of three non-coupled two-level atoms independently interacting with their reservoirs is solved exactly by considering a damping Lorentzian spectral density. For three atoms initially prepared in Greenberger—Horne—Zeilinger-type state, quantum correlation dynamics in a Markovian reservoir is compared with that in a non-Markovian reservoir. By increasing detuning quantity in the non-Markovian reservoir, three-atom correlation dynamics measured by negative eigenvalue presents a trapping phenomenon which provides long-time quantum entanglement. Then we compare the correlation dynamics of three atoms with that of two atoms, measured by quantum entanglement and quantum discord for an initial robuster-entangled type state. The result further confirms that quantum discord is indeed different from quantum entanglement in identifying quantum correlation of many bodies.

Chinese Physics B•Feb 1, 2013•5 citations

Non-Markovian dynamics of quantum discord

F. F. Fanchini, T. Werlang, Carlos Alexandre Brasil +2 more

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.

arXiv:0911.1096•Physical Review A•May 11, 2010•464 citations

Quantum correlation dynamics of two two-level atoms in common environment

He Zhi, Li Long-Wu

By exactly solving the model of two two-level atoms with dipole-dipole interaction, interacting with a common environment, quantum entanglement and quantum discord of two atoms are obtained. In this paper, the influences of the non-Markovian effect of environment, the dipole-dipole interaction of two atoms and the detunings of the central frequency of the cavity and the transition frequency of the atoms on quantum entanglement and quantum discord dynamics of two atoms are comprehensively considered. The study shows that in the non-Markovian regime and the resonant case, if two atoms are initially in the entangled state, the damping of quantum entanglement and quantum discord will be remarkably suppressed. More specially, in the off-resonant case, the disentanglement time of the two atoms can be considerably prolonged. On the other hand, if two atoms are initially in the separable state, the dipole-dipole interaction can enhance the amplitude of oscillations of quantum entanglement and quantum discord in a short time, but the steady values of quantum entanglement and quantum discord cannot be changed by the dipole-dipole interaction in the long-time limit. Finally, the different influences of the dipole-dipole interaction on quantum entanglement and quantum discord also are discussed.

Acta Physica Sinica•Jan 1, 2013•9 citations

Discord and entanglement in non-Markovian environments at finite temperatures

Hong-Mei Zou, Mao-Fa Fang

The dynamic evolutions of the discord and entanglement of two atoms immersed in two independent Lorentzian reservoirs at zero and finite temperatures have been investigated by using the time-convolutionless master-equation method. Our results show that, nonzero temperature can induce the entanglement sudden death and accelerate the decays of discord and entanglement. The discord and the entanglement have different robustness for different initial states and their robustness may change under certain conditions. When both the non-Markovian effect and detuning are present simultaneously, due to the memory and feedback effect of non-Markovian reservoirs, the discord and entanglement can be effectively protected even at nonzero temperature by increasing the non-Markovian effect and the detuning.

arXiv:1905.06624•Chinese Physics B•Aug 30, 2016•10 citations
The quantum discord dynamics of two non-coupled two-level atoms independently interacting with their reservoir is studied under two kinds of non-Markovian conditions, namely, an off-resonant case with atomic transition frequency and a photonic band gap. In the first case, the phenomenon of the quantum discord loss and the oscillatory behavior of the quantum discord can occur by changing the detuning quantity and reducing the spectral coupling width for any initial Bell state. Under the second condition, the trapping phenomenon of the quantum discord can be presented by adjusting the width of gap, that is, the quantum discord of two atoms keep a nonzero constant for a long time.
The dynamics of two non-coupled qubits independently interacting with their reservoirs is solved by the time convolutionless projection operator method. We study two-qubit quantum correlation dynamics for two different types of spectral densities, which are a Lorentzian distribution and an Ohmic spectral density with a Lorentzian—Drude cutoff function. For two qubits initially prepared in the initial Bell state, quantum discord can keep longer time and reach larger values in non-Markovian reservoirs for the first spectral distribution or by reducing the cutoff frequency for the second case. For the initial Bell-like state, the dynamic behaviors of quantum discord and entanglement are compared. The results show that a long time of quantum correlation can be obtained by adjusting some parameters in experiment and further confirm that the discord can capture quantum correlation in addition to entanglement.
We investigate the dynamics of pairwise quantum discord (QD) for a mixed three-qubit W-type state in three independent non-Markovian reservoirs at zero temperature, each of which is modeled by a leaky cavity with Lorentzian spectral density. The influence of the environment's amount of non-Markovianity, the detuning between the qubit frequency and the cavity centre frequency, and the purity of the initial state on the QD dynamics are analyzed in detail. It is found that in the non-Markovian regime the system-reservoir interactions induce QD revivals and oscillations no matter whether the detuning is zero or not. Moreover, QD can be preserved for a long time if the non-Markovian condition and the detuning condition are satisfied simultaneously.
Time evolution dynamics of three non-coupled two-level atoms independently interacting with their reservoirs is solved exactly by considering a damping Lorentzian spectral density. For three atoms initially prepared in Greenberger—Horne—Zeilinger-type state, quantum correlation dynamics in a Markovian reservoir is compared with that in a non-Markovian reservoir. By increasing detuning quantity in the non-Markovian reservoir, three-atom correlation dynamics measured by negative eigenvalue presents a trapping phenomenon which provides long-time quantum entanglement. Then we compare the correlation dynamics of three atoms with that of two atoms, measured by quantum entanglement and quantum discord for an initial robuster-entangled type state. The result further confirms that quantum discord is indeed different from quantum entanglement in identifying quantum correlation of many bodies.
We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.
By exactly solving the model of two two-level atoms with dipole-dipole interaction, interacting with a common environment, quantum entanglement and quantum discord of two atoms are obtained. In this paper, the influences of the non-Markovian effect of environment, the dipole-dipole interaction of two atoms and the detunings of the central frequency of the cavity and the transition frequency of the atoms on quantum entanglement and quantum discord dynamics of two atoms are comprehensively considered. The study shows that in the non-Markovian regime and the resonant case, if two atoms are initially in the entangled state, the damping of quantum entanglement and quantum discord will be remarkably suppressed. More specially, in the off-resonant case, the disentanglement time of the two atoms can be considerably prolonged. On the other hand, if two atoms are initially in the separable state, the dipole-dipole interaction can enhance the amplitude of oscillations of quantum entanglement and quantum discord in a short time, but the steady values of quantum entanglement and quantum discord cannot be changed by the dipole-dipole interaction in the long-time limit. Finally, the different influences of the dipole-dipole interaction on quantum entanglement and quantum discord also are discussed.
The dynamic evolutions of the discord and entanglement of two atoms immersed in two independent Lorentzian reservoirs at zero and finite temperatures have been investigated by using the time-convolutionless master-equation method. Our results show that, nonzero temperature can induce the entanglement sudden death and accelerate the decays of discord and entanglement. The discord and the entanglement have different robustness for different initial states and their robustness may change under certain conditions. When both the non-Markovian effect and detuning are present simultaneously, due to the memory and feedback effect of non-Markovian reservoirs, the discord and entanglement can be effectively protected even at nonzero temperature by increasing the non-Markovian effect and the detuning.