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 B

Phase effect on dynamics of quantum discord modulated by interaction between qubits

Guoyou Wang, You-neng Guo, Hao‐Sheng Zeng

Published Sep 1, 2015• 0 citations
Publisher

Abstract

We study the effects of the interaction strength and the initial phase on the dynamics of quantum discord in a two-qubit system under both spontaneous emission and dephasing noisy channels. It is shown that the time evolution of quantum discord displays quicker oscillations with increasing inter-qubit interaction strength but the effect of the initial phase closely depends on the interaction between the qubits. Only for non-zero inter-qubit interaction cases, the evolution of quantum discord is affected by the initial phase and its oscillating amplitude increases with increasing initial phase. A comparison between evolutions of quantum discord and entanglement is also made.

DOI
10.1088/1674-1056/24/9/090303

Related papers

Dissipative dynamics of quantum discord under quantum chaotic environment

Yuan Xu, Wanli Yang, Mang Feng

We investigate the dissipative dynamics of quantum discord in a decoherence model with two initially entangled qubits in addition to a quantum kicked top. The two qubits are uncoupled during the period of our study and one of them interacts with the quantum kicked top. We find that the long-time behavior of quantum discord could be well described by the fidelity decay of the quantum kicked top; for short-time behavior, however, the phase of the amplitude of the fidelity decay is necessary to provide more specific information about the system. We have made a comparison between the quantum kicked top and the multi-mode oscillator system in describing the environment, and also compared the dynamics of the entanglement with that of quantum discord.

arXiv:1010.3789•Europhysics Letters (EPL)•Oct 1, 2010•8 citations

Dynamics of the Quantum Correlation of Qubits Dissipating into a Common Environment

Xiao-San Ma, Ying Qiao, Xiaodong Liu +1 more

In this paper, we have investigated the dynamics of the quantum correlation between two qubits of a system composed of an arbitrary number of qubits dissipating into a common environment. Our results imply that, when the initial state of the system contains one excitation, the quantum correlation of the quantum discord and the entanglement of formation can be generated between two qubits which have no interaction with each other but are interacting with a common environment. From our analysis, we find that the dynamics of the quantum discord and the entanglement of formation depends not only on the scaled time but also on the size of the system. The larger the size of the system is, the less the quantum discord and the entanglement of formation is generated. By using a comparison between the quantum discord and the entanglement of formation, we find that the quantum discord is more robust to the size of the system than the entanglement of formation is, in the sense that the former decreases more slowly with an increase of the size of the system than the latter does. In addition, the case of the initial state with two excitations is discussed.

Chinese Journal of Physics•Feb 1, 2014•0 citations

Dynamics of correlations due to a phase noisy laser

Bruno Bellomo, Rosario Lo Franco, Erika Andersson +1 more

We analyze the dynamics of various kinds of correlations present between two initially entangled independent qubits, each one subject to a local phase-noisy laser. We give explicit expressions for the relevant quantifiers of correlations for the general case of single-qubit unital evolution, which includes the case of a phase-noisy laser. Although the light field is treated as classical, we find that this model can describe revivals of quantum correlations. Two different dynamical regimes of decay of correlations occur, a Markovian one (exponential decay) and a non-Markovian one (oscillatory decay with revivals) depending on the values of system parameters. In particular, in the non-Markovian regime, quantum correlations quantified by quantum discord show an oscillatory decay faster than that of classical correlations. Moreover, there are time regions where nonzero discord is present while entanglement is zero.

•Aug 14, 2016•25 citations

Quantum Zeno effect on Quantum Discord

Alagu Thilagam

We examine the quantum Zeno effect on the dynamics of quantum discord in two initially entangled qubits which are subjected to frequent measurements via decoherent coupling with independent reservoirs. The links between characteristic parameters such as system bias, measurement time duration, strength of initial entanglement between the two qubit systems and the dynamics of quantum discord are examined in the case of two initial state configurations. For weak or unsharp measurements, the quantum discord, which is an intrinsically distinct entity from concurrence, serves as a reliable indicator of the crossover point in Zeno to anti-Zeno transitions. However at highly precise quantum measurements, the monitoring device interferes significantly with the evolution dynamics of the monitored system, and the quantum discord yields indeterminate values in a reference frame where the observer is not an active constituent of the subsystems.

arXiv:1011.5901•Nov 25, 2010•0 citations

Quantum discord dynamics in the presence of initial system–bath correlations

Lin Li, Jian Zou, Bao-Ming Xu +4 more

We investigate the influence of the initial correlations between a two-qubit system and a family of baths on the dynamics of quantum discord of these two qubits. We show that the initial states with entanglement between the two-qubit system and the bath can prompt two qubits to gain more quantum discord. Moreover, for the initial states only with discord but null entanglement between the two-qubit system and the bath, the effects depend on whether two qubits or one of the two qubits interact with the bath. We also find that there exist some specific initial states for which the entanglement between two qubits is invariant as time evolves, but the quantum discord is not, and for some other initial states although the states evolve, both the entanglement and the quantum discord remain invariant.

Physica Scripta•Nov 5, 2012•7 citations

Dynamics of correlations due to a phase-noisy laser

Bruno Bellomo, Rosario Lo Franco, Erika Andersson +2 more

We analyze the dynamics of various kinds of correlations present between two initially entangled independent qubits, each one subject to a local phase-noisy laser. We give explicit expressions for the relevant quantifiers of correlations for the general case of single-qubit unital evolution, which includes the case of a phase-noisy laser. Although the light field is treated as classical, we find that this model can describe revivals of quantum correlations. Two different dynamical regimes of decay of correlations occur, a Markovian one (exponential decay) and a non-Markovian one (oscillatory decay with revivals) depending on the values of system parameters. In particular, in the non-Markovian regime, quantum correlations quantified by quantum discord show an oscillatory decay faster than that of classical correlations. Moreover, there are time regions where nonzero discord is present while entanglement is zero.

arXiv:1111.0917•Physica Scripta•Feb 1, 2012•32 citations
We study the effects of the interaction strength and the initial phase on the dynamics of quantum discord in a two-qubit system under both spontaneous emission and dephasing noisy channels. It is shown that the time evolution of quantum discord displays quicker oscillations with increasing inter-qubit interaction strength but the effect of the initial phase closely depends on the interaction between the qubits. Only for non-zero inter-qubit interaction cases, the evolution of quantum discord is affected by the initial phase and its oscillating amplitude increases with increasing initial phase. A comparison between evolutions of quantum discord and entanglement is also made.
We investigate the dissipative dynamics of quantum discord in a decoherence model with two initially entangled qubits in addition to a quantum kicked top. The two qubits are uncoupled during the period of our study and one of them interacts with the quantum kicked top. We find that the long-time behavior of quantum discord could be well described by the fidelity decay of the quantum kicked top; for short-time behavior, however, the phase of the amplitude of the fidelity decay is necessary to provide more specific information about the system. We have made a comparison between the quantum kicked top and the multi-mode oscillator system in describing the environment, and also compared the dynamics of the entanglement with that of quantum discord.
In this paper, we have investigated the dynamics of the quantum correlation between two qubits of a system composed of an arbitrary number of qubits dissipating into a common environment. Our results imply that, when the initial state of the system contains one excitation, the quantum correlation of the quantum discord and the entanglement of formation can be generated between two qubits which have no interaction with each other but are interacting with a common environment. From our analysis, we find that the dynamics of the quantum discord and the entanglement of formation depends not only on the scaled time but also on the size of the system. The larger the size of the system is, the less the quantum discord and the entanglement of formation is generated. By using a comparison between the quantum discord and the entanglement of formation, we find that the quantum discord is more robust to the size of the system than the entanglement of formation is, in the sense that the former decreases more slowly with an increase of the size of the system than the latter does. In addition, the case of the initial state with two excitations is discussed.
We analyze the dynamics of various kinds of correlations present between two initially entangled independent qubits, each one subject to a local phase-noisy laser. We give explicit expressions for the relevant quantifiers of correlations for the general case of single-qubit unital evolution, which includes the case of a phase-noisy laser. Although the light field is treated as classical, we find that this model can describe revivals of quantum correlations. Two different dynamical regimes of decay of correlations occur, a Markovian one (exponential decay) and a non-Markovian one (oscillatory decay with revivals) depending on the values of system parameters. In particular, in the non-Markovian regime, quantum correlations quantified by quantum discord show an oscillatory decay faster than that of classical correlations. Moreover, there are time regions where nonzero discord is present while entanglement is zero.
We examine the quantum Zeno effect on the dynamics of quantum discord in two initially entangled qubits which are subjected to frequent measurements via decoherent coupling with independent reservoirs. The links between characteristic parameters such as system bias, measurement time duration, strength of initial entanglement between the two qubit systems and the dynamics of quantum discord are examined in the case of two initial state configurations. For weak or unsharp measurements, the quantum discord, which is an intrinsically distinct entity from concurrence, serves as a reliable indicator of the crossover point in Zeno to anti-Zeno transitions. However at highly precise quantum measurements, the monitoring device interferes significantly with the evolution dynamics of the monitored system, and the quantum discord yields indeterminate values in a reference frame where the observer is not an active constituent of the subsystems.
We investigate the influence of the initial correlations between a two-qubit system and a family of baths on the dynamics of quantum discord of these two qubits. We show that the initial states with entanglement between the two-qubit system and the bath can prompt two qubits to gain more quantum discord. Moreover, for the initial states only with discord but null entanglement between the two-qubit system and the bath, the effects depend on whether two qubits or one of the two qubits interact with the bath. We also find that there exist some specific initial states for which the entanglement between two qubits is invariant as time evolves, but the quantum discord is not, and for some other initial states although the states evolve, both the entanglement and the quantum discord remain invariant.
We analyze the dynamics of various kinds of correlations present between two initially entangled independent qubits, each one subject to a local phase-noisy laser. We give explicit expressions for the relevant quantifiers of correlations for the general case of single-qubit unital evolution, which includes the case of a phase-noisy laser. Although the light field is treated as classical, we find that this model can describe revivals of quantum correlations. Two different dynamical regimes of decay of correlations occur, a Markovian one (exponential decay) and a non-Markovian one (oscillatory decay with revivals) depending on the values of system parameters. In particular, in the non-Markovian regime, quantum correlations quantified by quantum discord show an oscillatory decay faster than that of classical correlations. Moreover, there are time regions where nonzero discord is present while entanglement is zero.