共查询到20条相似文献,搜索用时 15 毫秒
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Chuan-Jia Shan Tao Chen Ji-Bing Liu Wei-Wen Cheng Tang-Kun Liu Yan-Xia Huang Hong Li 《International Journal of Theoretical Physics》2010,49(4):717-727
The decoherence and the decay of quantum entanglement due to both population relaxation and thermal effects are investigated
for the two qubits initially prepared in the extended Werner-like state by solving the Lindblad form of the master equation,
where each qubit is interacting with an independent reservoir at finite temperature T. Entanglement sudden death (ESD) and entanglement sudden birth (ESB) are observed during the evolution process. We analyze
in detail the effects of the mixedness, the degree of entanglement of the initial states and finite temperature on the time
of entanglement sudden death and entanglement sudden birth. We also obtain an analytic formula for the steady state concurrence
that shows its dependence on both the system parameters, the decoherence rate and finite temperature. These results arising
from the combination of extended Werner-like initial state and independent thermal reservoirs suggest an approach to control
the maximum possible concurrence even after the purity and finite temperature induce sudden birth, death and revival. 相似文献
3.
We study the entanglement dynamics between two strongly-AC-driven superconducting charge qubits coupled collectively to a zero temperature, dissipative resonator and find an unusual feather that the competing of creation and annihilation of entanglement can lead to entanglement increasing, sudden death and revival. We also calculate the dependence of the death time on the initial state of the system. 相似文献
4.
Sudden birth versus sudden death of entanglement for the extended Werner-like state in a dissipative environment
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In this paper, we investigate the dynamical behaviour of
entanglement in terms of concurrence in a bipartite system
subjected to an external magnetic field under the action of
dissipative environments in the extended Werner-like initial state.
The interesting phenomenon of entanglement sudden death as well as
sudden birth appears during the evolution process. We analyse in
detail the effect of the purity of the initial entangled state of two qubits
via Heisenberg XY interaction on the apparition time of entanglement
sudden death and entanglement sudden birth. Furthermore, the
conditions on the conversion of entanglement sudden death and
entanglement sudden birth can be generalized when the initial
entangled state is not pure. In particular, a critical purity of the
initial mixed entangled state exists, above which entanglement
sudden birth vanishes while entanglement sudden death appears. It is
also noticed that stable entanglement, which is independent of
different initial states of the qubits (pure or mixed state), occurs
even in the presence of decoherence. These results arising from the
combination of the extended Werner-like initial state and dissipative
environments suggest an approach to control and enhance the
entanglement even after purity induced sudden birth, death and
revival. 相似文献
5.
SHAN Chuan-Jia LIU Ji-Bing CHEN Tao CHENG Wei-Wen LIU Tang-Kun HUANG Yan-Xia LI Hong 《理论物理通讯》2010,54(3):427-432
We investigate the sudden birth and sudden death of entanglement of two qubits interacting with uncorrelated structured reservoirs. The system is initially prepared in two-qubit extended Werner-like state. We work out the dependence of the entanglement dynamics on both non-Markovian environments and the purity of initial state, and show that non-Markovian environments and the purity can control the time of the two-qubit entanglement sudden death and the reservoirs' entanglement sudden birth.Furthermore, under the conditions of different purity and initial entanglement, the revival of qubits' entanglement can manifest before, simultaneously or even after the disentanglement of their corresponding reservoirs. 相似文献
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We investigate the entanglement dynamics of two initially entangled qubits interacting independently with two uncorrelated reservoirs beyond the Markovian approximation. Quite different from the Markovian reservoirs [C.E. López, et al., Phys. Rev. Lett. 101 (2008) 080503], we find that entanglement sudden birth (ESB) of the two reservoirs occurs without certain symmetry with respect to the entanglement sudden death (ESD) of the two qubits. A phenomenological interpretation of entanglement revival is also given. 相似文献
8.
We consider entanglement dynamics of double intensity-dependent coupling Jaynes-Cummings models with two different initial
light fields, which one is in the squeezed vacuum state and another is in the coherent state. The results show that, when
the compressibility factor and the mean photon number are smaller, the concurrence of atoms exhibits phenomenon of dead and
revival periodically, and the entanglement perfectly transferres between the atoms and the fields. As the value of them grow
larger, the entanglement sudden death and sudden revival come out. Comparing with the normal double Jaynes-Cummings model,
we notice that the concurrence of the atoms which in the normal double Jaynes-Cummings models evolves irregularly. And it
is find that periodical entanglement pulse can be generated by using double intensity-dependent coupling Jaynes-Cummings models.
This result might be useful in quantum information processes. 相似文献
9.
We present a general and fascinating problem of quantum entanglement (QE) that is calculated with the help of quantum Fisher information (QFI) and von Neumann entropy (VNE) for moving two-level atomic systems. We calculate numerically the temporal evolution of the state vector of the entire system under the influence of intrinsic decoherence for a moving two-level atom. We demonstrate that the phase shifts of an estimator parameter, intrinsic decoherence, and the atomic motion play an important and prominent role during the time evolution of the atomic system. We observe that there is a monotonic relation between the atomic quantum Fisher information (QFI) and quantum entanglement (QE) in the absence of atomic motion. We also show that at the revival time the local maximum values of QFI decreases gradually. A periodic behavior of QFI is observed in the presence of atomic motion, which becomes more important and remarkable for two-level atomic systems. Moreover, the atomic quantum Fisher information and entanglement demonstrate an opposite response during the time evolution in the presence of atomic motion. We show that the evolution of entanglement is more susceptible to the intrinsic decoherence; a considerable change occurs in the degree of entanglement when the intrinsic decoherence parameter increases. Intrinsic decoherence in the atom–field interaction represses the nonclassical effects of the atomic systems. Both the entanglement and the quantum Fisher information saturate to their lower levels for longer time scales in the presence of intrinsic decoherence. For larger values of intrinsic decoherence, the sudden death of entanglement is observed. 相似文献
10.
Quantum correlations between two non-interacting atoms under the influence of a thermal environment
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By considering a double Jaynes-Cummings model, we investigate the dynamics of quantum correlations, such as the quantum discord and the entanglement, for two atoms in their respective noisy environments, and study the effect of the purity and the cavity temperature on the quantum correlations. The results show that the entanglement suffers sudden death and revival, however the quantum discord can still reveal the quantum correlations between the two atoms in the region where the entanglement is zero. Moreover, when the temperature of each cavity is high the entanglement dies out in a short time, but the quantum discord still survives for quite a long time. It means that the quantum discord is more resistant to environmental disturbance than the entanglement at higher temperatures. 相似文献
11.
J. S. Zhang L. Chen M. Abdel-Aty A. X. Chen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2012,66(1):2
We study the dynamics of quantum discord and entanglement of two entangled two-level
atoms within two isolated and dissipative cavities in the weak- or strong-coupling regime.
The quantum entanglement are measured by concurrence and relative entropy. The quantum
discord of two atoms based on quantum mutual information and relative entropy are also
calculated. In the weak-coupling regime, the sudden death of quantum discord and
entanglement of two atoms can occur simultaneously within a short interaction time. When
the interaction time is long, quantum discord and entanglement of two atoms could be
partially preserved due to the long-lived nature of quantum discord and entanglement.
However, in the strong-coupling regime, there is no sudden death of quantum discord though
the entanglement sudden death phenomenon occurs. In addition, we observe that entanglement
and discord will be destroyed eventually when the atom-field interactions are strong. We
also address the issue of experimental realization briefly. 相似文献
12.
Sudden death of entanglement: Classical noise effects 总被引:2,自引:0,他引:2
When a composite quantum state interacts with its surroundings, both quantum coherence of individual particles and quantum entanglement will decay. We have shown that under vacuum noise, i.e., during spontaneous emission, two-qubit entanglement may terminate abruptly in a finite time [T. Yu, J.H. Eberly, Phys. Rev. Lett. 93 (2004) 140404], a phenomenon termed entanglement sudden death (ESD). An open issue is the behavior of mixed-state entanglement under the influence of classical noise. In this paper we investigate entanglement sudden death as it arises from the influence of classical phase noise on two qubits that are initially entangled but have no further mutual interaction. 相似文献
13.
A system of two initially entangled qubits interacting with a bosonic environment is considered. The interaction induces a loss of the initial entanglement of the two qubits, and for specific initial states it causes entanglement sudden death. An investigation of the modifications on the entanglement dynamics by a single pulse control field, performed in the two qubit system, shows that the control field can not only protect entangled states against sudden death but also induce a revival of entanglement in the two qubit system. 相似文献
14.
The dynamics of a superconducting (SC) qubit interacting with a field under decoherence with and without time-dependent coupling effect is analyzed. Quantum features like the collapse–revivals for the dynamics of population inversion, sudden birth and sudden death of entanglement, and statistical properties are investigated under the phase damping effect. Analytic results for certain parametric conditions are obtained. We analyze the influence of decoherence on the negativity and Wehrl entropy for different values of the physical parameters. We also explore an interesting relation between the SC-field entanglement and Wehrl entropy behavior during the time evolution. We show that the amount of SC-field entanglement can be enhanced as the field tends to be more classical. The studied model of SC-field system with the time-dependent coupling has high practical importance due to their experimental accessibility which may open new perspectives in different tasks of quantum formation processing. 相似文献
15.
We investigate the dynamics of two identical atoms resonantly coupled to independent single-mode cavity in zero detuning without rotating wave approximation (RWA). It is shown that for two atoms initially in the ground state, the entanglement (concurrence) and the normalized geometric measure of quantum discord (NGMQD) display similar behavior. There is no sudden death and sudden birth. And the entanglement is always larger than NGMQD in this case. For two atoms initially in excited state, one can see the novel entanglement sudden death (ESD) and sudden birth (ESB) phenomena. The entanglement is not always greater than the NGMQD in this case. Consequently, there is no simple dominance relation between the entanglement and the NGMQD. 相似文献
16.
Exact solution of entanglement of the double Jaynes-Cummings model without rotating wave approximation
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This paper investigates the influences of atom-field coupling and dipole-dipole coupling for atoms on the entanglement between two atoms by means of concurrence. The results show that the sudden death occurs when the atom-field coupling is strong enough, and the collapse and the revival appear when the dipole-dipole interaction is strong enough. 相似文献
17.
Hünkar Kayhan 《理论物理通讯》2011,56(3):487-489
We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit time-dependence is considered for the case of the linear sweep. We show that the sudden death of entanglement can be controlled by the transient effects. These effects can suppress the sudden death of entanglement in time. 相似文献
18.
The dynamics of a superconducting (SC) qubit interacting with a field under decoherence with and without time-dependent coupling effect is analyzed. Quantum features like the collapse–revivals for the dynamics of population inversion, sudden birth and sudden death of entanglement, and statistical properties are investigated under the phase damping effect. Analytic results for certain parametric conditions are obtained. We analyze the influence of decoherence on the negativity and Wehrl entropy for different values of the physical parameters. We also explore an interesting relation between the SC-field entanglement and Wehrl entropy behavior during the time evolution. We show that the amount of SC-field entanglement can be enhanced as the field tends to be more classical. The studied model of SC-field system with the time-dependent coupling has high practical importance due to their experimental accessibility which may open new perspectives in different tasks of quantum formation processing. 相似文献
19.
研究了初态为X态时Tavis-Cummings模型中具有偶极相互作用两原子的纠缠演化特性,在演化过程中,同时号码出现了两原子的纠缠突然死亡(ESD)与突然产生(ESB)两种有趣的现象.详细分析了两原子初始态的纯度、偶极相互作用、光场粒子数对这两种现象出现时间的影响,进一步给出了初始为混态时ESB与ESD的转换条件.计算结果表明,上述系统参量对两原子的纠缠演化、ESB与ESD有重要的影响,偶极相互作用会改变纠缠度的振荡周期,使出现ESD的时间间隔减少;随着初始两原子纠缠纯度的增大,纠缠突然产生以及纠缠突然死亡存在的时间缩短,并且可以提高两原子之间的纠缠;对于特殊的初态,产生了纠缠不变性以及固定的两原子纠缠,该定值受两原子初始状态的纯度控制。 相似文献
20.
The evolution of entanglement decoherence is investigated for a coupled superconducting qubit under non-Markovian environment
by utilizing a commensal entanglement degree. The results show that, owing to the memory feedback effect of environment, the
entanglement degree of the coupled qubits at the thermal equilibrium always monotonously tends to zero so that entanglement
sudden death occurs briefly in the non-Markovian process. Different from the Markovian process, stronger the dissipation is,
faster the entanglement sudden death is. We find that, furthermore, the interaction between the qubits results generally in
reduction of entanglement degree in the quantum system. With some special initial states or initial phase angles, however,
the influence of the interaction between qubits on the system entanglement degree can be avoided. 相似文献