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

Acta Sinica Quantum Optica

Spatial Decoherence Dynamics of Two Qubits Induced by Initial States of Cavity field

Zheng Tai-Yu

Published Jan 1, 2012• 0 citations
OpenAlex

Abstract

We study the spatial decoherence dynamics for the relative position of two atoms interacting with a single-mode cavity which are assumed initially in three different states.It is assumed that the atomic relative position is in the state of a superposition of two Gaussian wave packets and that the cavity field is initially in thermal state,Fock state and squeezed state respectively.Based on the reduced density matrix for the atomic relative position,we study the influence of the atom-field interaction on the quantum coherence of atomic relative position.We find that for different initial states of the cavity field,the quantum decoherence dynamics of the atomic relative position is different.When the cavity field is initially in a thermal state or Fock state,the spatial coherence oscillates with decay and revival periodically,while when the cavity field is initially in a squeezed state,the spatial coherence of the two-atom relative position is partially destroyed,and the decay degree is connected with the value of the atomic relative position in a cosine law.

Related papers

Quantum dynamics of spatial decoherence of two atoms in a ring cavity

Zheng Li, Chui-Ping Yang, Franco Nori

We study the spatial decoherence dynamics for the relative position of two atoms in a single-mode ring cavity. We find that the spatial decoherence of the two atoms depends strongly on their relative position. Taking into account the spatial degrees of freedom, we investigate the entanglement dynamics of the internal states of the two atoms. It is shown that the entanglement decays to almost zero in a finite time, and the disentanglement time depends on the width of the wave packets describing the atomic spatial distribution.

arXiv:1101.0032•Physical Review A•Dec 7, 2010•21 citations

Entanglement for two qubits induced by one-mode thermal field in the presence of the atomic coherence

Eugene K. Bashkirov, Башкиров Е. К, Michail S. Mastyugin +1 more

In the prresent paper we have considered the influence of the initial atomic coherence on entanglement dynamics of two qubits one of which is trapped in a lossless cavity and interacts with single-mode thermal field, and the other one can be spatially moved freely outside the cavity. We have shown that the atomic coherence in the model under the consideration can be used for effective control on the degree of the entanglement of qubits.

Physics of Wave Processes and Radio Systems•Jun 15, 2015•0 citations

Entanglement of atoms induced by thermal noise in the presence of initial atomic coherence

Евгений Константинович Башкиров

In this article, author investigated the dynamics of entanglement of two dipole-coupled natural or artificial two-level atoms (qubits) interacting nonresonantly with the intensive one-mode cavity thermal field. Author found an exact solution of the quantum Liouville equation for the full density matrix of the system two atoms + field mode for a coherent initial state of atoms in the dressed states representation. The full system density matrix is used to calculate the two-atom reduced density matrix and to calculate the quantitative criterion for atom-atom entanglement ‒ negativity. The results of computer simulation of the time dependence of negativity showed that in the case of a model with nonresonant interaction, the presence of initial atomic coherence leads to a significant decrease in the maximum degree of atomic entanglement, in contrast to the model with resonant interaction of atoms and a field. For the resonance model, the initial atomic coherence greatly enhances the degree of atomic entanglement.

Physics of Wave Processes and Radio Systems•Sep 27, 2020•1 citation

Quantum Decoherence of the Relative Position Between Two Atoms in the Two-mode Squeezed States

Yang Liu

By the full quantum theory,the dynamical evolution of the motion of C.M of two atoms in the two-mode squeezed vacuum states was studied.Through caculating,the reduced density matrix of the relative position of two atoms and decoherence factor were obtained.It was found out:1)the spontaneous radiation of the couple of atoms could induce the decoherence for the motion of C.M in the two-mode squeezed vacuum state;2)the phenomenon of quantum decoherence became more clear with the squeezed factor changing bigger.

Journal of Jimei University•Jan 1, 2008•0 citations

Quantum coherence in a coupled-cavity array

De-Wei Cao, Yixin Zhang, Jicheng Wang +1 more

The dynamical properties of quantum coherence in the system of two-coupled-cavities, each of which resonantly interacts with a two-level atom, is investigated via the relative entropy measure. We focus on the coherences for the atom–atom, atom–cavity and cavity–cavity subsystems and find that the dynamical behaviors of these coherences depend largely on the cavity–cavity coupling, which may indicate the Mott insulator-superfluid transition in the thermodynamic limit. We also study the influences of the initial cavity–cavity correlation on the coherences and show that the initial correlation of the cavity–cavity subsystem can enhance the revival ability for the atom–atom and cavity–cavity coherences while reduce that for the atom–cavity coherence. Besides, we demonstrate the qualitative difference of dynamics between coherence and entanglement. Finally, the influences of dissipations including cavity losses and atomic decays on the coherence are explored.

International Journal of Modern Physics B•May 6, 2016•0 citations

Entanglement between two qubits induced by thermal field

Eugene K. Bashkirov, Michail S. Mastyugin

We have investigated the influence of dipole-dipole interaction and initial atomic coherence on atomic entanglement dynamics of two qubits. We have considered a model, in which only one atom couples to a quantum electromagnetic field in a cavity, since one of them can move around the cavity. We have shown that the entanglement arises for all pure atomic state even when both atoms are initially in the excited states. We have also derived that degree of entanglement is enhanced in the presence of the atomic coherence.

Journal of Physics Conference Series•Aug 1, 2016•11 citations
We study the spatial decoherence dynamics for the relative position of two atoms interacting with a single-mode cavity which are assumed initially in three different states.It is assumed that the atomic relative position is in the state of a superposition of two Gaussian wave packets and that the cavity field is initially in thermal state,Fock state and squeezed state respectively.Based on the reduced density matrix for the atomic relative position,we study the influence of the atom-field interaction on the quantum coherence of atomic relative position.We find that for different initial states of the cavity field,the quantum decoherence dynamics of the atomic relative position is different.When the cavity field is initially in a thermal state or Fock state,the spatial coherence oscillates with decay and revival periodically,while when the cavity field is initially in a squeezed state,the spatial coherence of the two-atom relative position is partially destroyed,and the decay degree is connected with the value of the atomic relative position in a cosine law.
We study the spatial decoherence dynamics for the relative position of two atoms in a single-mode ring cavity. We find that the spatial decoherence of the two atoms depends strongly on their relative position. Taking into account the spatial degrees of freedom, we investigate the entanglement dynamics of the internal states of the two atoms. It is shown that the entanglement decays to almost zero in a finite time, and the disentanglement time depends on the width of the wave packets describing the atomic spatial distribution.
In this article, author investigated the dynamics of entanglement of two dipole-coupled natural or artificial two-level atoms (qubits) interacting nonresonantly with the intensive one-mode cavity thermal field. Author found an exact solution of the quantum Liouville equation for the full density matrix of the system two atoms + field mode for a coherent initial state of atoms in the dressed states representation. The full system density matrix is used to calculate the two-atom reduced density matrix and to calculate the quantitative criterion for atom-atom entanglement ‒ negativity. The results of computer simulation of the time dependence of negativity showed that in the case of a model with nonresonant interaction, the presence of initial atomic coherence leads to a significant decrease in the maximum degree of atomic entanglement, in contrast to the model with resonant interaction of atoms and a field. For the resonance model, the initial atomic coherence greatly enhances the degree of atomic entanglement.
By the full quantum theory,the dynamical evolution of the motion of C.M of two atoms in the two-mode squeezed vacuum states was studied.Through caculating,the reduced density matrix of the relative position of two atoms and decoherence factor were obtained.It was found out:1)the spontaneous radiation of the couple of atoms could induce the decoherence for the motion of C.M in the two-mode squeezed vacuum state;2)the phenomenon of quantum decoherence became more clear with the squeezed factor changing bigger.
The dynamical properties of quantum coherence in the system of two-coupled-cavities, each of which resonantly interacts with a two-level atom, is investigated via the relative entropy measure. We focus on the coherences for the atom–atom, atom–cavity and cavity–cavity subsystems and find that the dynamical behaviors of these coherences depend largely on the cavity–cavity coupling, which may indicate the Mott insulator-superfluid transition in the thermodynamic limit. We also study the influences of the initial cavity–cavity correlation on the coherences and show that the initial correlation of the cavity–cavity subsystem can enhance the revival ability for the atom–atom and cavity–cavity coherences while reduce that for the atom–cavity coherence. Besides, we demonstrate the qualitative difference of dynamics between coherence and entanglement. Finally, the influences of dissipations including cavity losses and atomic decays on the coherence are explored.
We have investigated the influence of dipole-dipole interaction and initial atomic coherence on atomic entanglement dynamics of two qubits. We have considered a model, in which only one atom couples to a quantum electromagnetic field in a cavity, since one of them can move around the cavity. We have shown that the entanglement arises for all pure atomic state even when both atoms are initially in the excited states. We have also derived that degree of entanglement is enhanced in the presence of the atomic coherence.