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

arXiv:1710.06154 · Physical Review A

Quenched dynamics of entangled states in correlated quantum dots

N. S. Maslova, P. I. Arseyev, Vladimir N. Mantsevich

Published Oct 2, 2017• 17 citations
arXivHTMLPDF

Abstract

The time evolution of an initially prepared entangled state in the system of coupled quantum dots has been analyzed by means of two different theoretical approaches: equations of motion for all orders localized electron correlation functions, considering interference effects, and kinetic equations for the pseudoparticle occupation numbers with constraint on the possible physical states. Results obtained by means of different approaches were carefully analyzed and compared to each other. Revealing a direct link between concurrence (degree of entanglement) and quantum dots pair correlation functions allowed us to follow the changes of entanglement during the time evolution of the coupled quantum dots system. It was demonstrated that the degree of entanglement can be controllably tuned during the time evolution of quantum dots system.

DOI
10.1103/physreva.96.042301

Related papers

Time evolution of entangled Bell states in coupled quantum dots in the presence of fluctuations

N. S. Maslova, Vladimir N. Mantsevich, Igor Michailovitsch Sokolov +1 more

We analyze the dynamics of two-qubit entangled Bell states in coupled quantum dots (QDs) in the presence of both fluctuations and coherent electron hopping between the dots. The explicit expression for time-dependent probability to find the system in the different Bell states was obtained for various initial conditions by means of Keldysh diagram technique. It was revealed that time evolution of one pair of Bell states and its decay rate strongly differs from another one. It was demonstrated that one pair of Bell states is more robust against fluctuations than another one. The stationary occupation of Bell states for different initial conditions was also analyzed. Obtained results are important for the problems where long-living Bell states are needed such as the security of quantum communication and quantum information processing.

Physical Review A•Mar 25, 2024•1 citation

Generation and evolution of entanglement in coupled quantum dots interacting with a quantized cavity field

Arnab Mitra, Reeta Vyas, Daniel B. Erenso

The generation of entanglement between two identical, interacting quantum dots---initially in ground states---by a coherent field and the subsequent time evolution of the entanglement are studied by calculating the concurrence between the two dots. The results predict that while it is possible to generate entanglement (or entanglement of formation, as defined for a mixed state) between the two dots, at no time do the dots become fully entangled to each other or is a maximally entangled Bell state ever achieved. We also observe that the degree of entanglement increases with an increase in the photon number inside the cavity and a decrease in the dot-photon coupling. The behavior of the two-dot system, initially prepared in an entangled state and interacting with thermal light, is also studied.

Physical Review A•Nov 20, 2007•16 citations

Dynamics of excitonic entanglement in a system of two quantum dots coupled to cavity field

Kehui Song

The dynamical behaviors of the entanglement for the excitons in a system of two coupled quantum dots and a single-mode cavity field are investigated for two different initial conditions by means of the concurrence.It is shown that the direct coupling between the dots can reduce the degree of the entanglement for the excitons.For the initial cavity field being in the odd-coherent state,the degree of their entanglement decreases with the increase of the coherent intensity of cavity field.There is a trade-off for excitonic entanglement when cavity field is initially prepared in the even-coherent state.The relation between the average photon numbers of cavity field and quasi-maximally entangled excitonic coherent states is studied.

Journal of Atomic and Molecular Physics•Jan 1, 2006•0 citations

Quench dynamics of correlated quantum dots

Dante Marvin Kennes, V. Meden

We study the relaxation dynamics of a quantum dot with local Coulomb correlations coupled to two noninteracting leads which are held in grand-canonical equilibrium. Only charge degrees of freedom are considered and the dot is described by a model which in the scaling limit becomes equivalent to the interacting resonant level model. We examine the time evolution of the current and the dot occupancy resulting from changes in the dot-lead coupling, the dots' on-site energy, or the charging energy. Abrupt and smooth parameter changes as well as setups with and without driving bias voltage are considered. For biased dots, we investigate the often studied response after turning on the dot-lead coupling but also the experimentally more relevant case in which the voltage is turned on. We identify and explain a variety of interesting many-body effects, and we clarify the role of initial correlations.

arXiv:1204.2100•Physical Review B•Jun 1, 2012•28 citations

Using Kondo entanglement to induce spin correlations between disconnected quantum dots

C. A. Büsser

We investigate the entanglement between the spins of two quantum dots that are not connected at once to the same system. Quantum entanglement between localized spins is an essential property for the development of quantum computing and quantum information. It is for this reason that generating and controlling an entangled state between quantum dots received great attention in the later years. In this work, we show that the information on the spin orientation of a quantum dot can be kept, using the Kondo entanglement, in a reservoir of electrons. Then, this information can be transmitted to another dot after the first dot has been uncoupled from the reservoirs. We use a double quantum dot system in a parallel geometry to construct the initial state, where each dot interacts with reservoirs of different symmetries. We chose a phase in the couplings to induce an antiferromagnetic spin correlation between the dots. The time evolution of the initial state has been analyzed using the time-dependent density matrix renormalization group method. We found that a partially entangled state between the dots can be obtained, even if they are not connected at the same time. This entangled state is formed just during the transient and is destroyed in the stationary state. The stability of the state found in the transient is shown. To understand the details of these phenomena, a canonical transformation of the real space is used.

arXiv:2303.17542•Mar 30, 2023•0 citations

Dynamics of quantum correlations in a quantum dot system with intrinsic decoherence effects

Essalha Chaouki, Zakaria Dahbi, Mostafa Mansour

In this paper, we explore the dynamics of quantum correlations in an isolated physical quantum dot under the influence of intrinsic decoherence (ID). We characterize quantum correlations in the quantum dot system using Concurrence to capture the amount of entanglement, and we use Trace Distance Discord (TDD) and Local Quantum Uncertainty (LQU) to measure nonclassical correlations. Likewise, we investigate the effect of ID on the temporal evolution of these quantifiers. In particular, the behavior of the two discord-like quantifiers in terms of the system parameters and the ID rate is investigated and analyzed in detail. We found that TDD and LQU behave similarly for different parameters characterizing the considered system and that TDD is more resistant than Concurrence and LQU against the ID effects. Our results also show that the robustness of quantum correlations can be modulated by adjusting the ID rate, quantum dot physical properties and initial conditions.

International Journal of Modern Physics B•Jul 11, 2022•22 citations
The time evolution of an initially prepared entangled state in the system of coupled quantum dots has been analyzed by means of two different theoretical approaches: equations of motion for all orders localized electron correlation functions, considering interference effects, and kinetic equations for the pseudoparticle occupation numbers with constraint on the possible physical states. Results obtained by means of different approaches were carefully analyzed and compared to each other. Revealing a direct link between concurrence (degree of entanglement) and quantum dots pair correlation functions allowed us to follow the changes of entanglement during the time evolution of the coupled quantum dots system. It was demonstrated that the degree of entanglement can be controllably tuned during the time evolution of quantum dots system.
We analyze the dynamics of two-qubit entangled Bell states in coupled quantum dots (QDs) in the presence of both fluctuations and coherent electron hopping between the dots. The explicit expression for time-dependent probability to find the system in the different Bell states was obtained for various initial conditions by means of Keldysh diagram technique. It was revealed that time evolution of one pair of Bell states and its decay rate strongly differs from another one. It was demonstrated that one pair of Bell states is more robust against fluctuations than another one. The stationary occupation of Bell states for different initial conditions was also analyzed. Obtained results are important for the problems where long-living Bell states are needed such as the security of quantum communication and quantum information processing.
The generation of entanglement between two identical, interacting quantum dots---initially in ground states---by a coherent field and the subsequent time evolution of the entanglement are studied by calculating the concurrence between the two dots. The results predict that while it is possible to generate entanglement (or entanglement of formation, as defined for a mixed state) between the two dots, at no time do the dots become fully entangled to each other or is a maximally entangled Bell state ever achieved. We also observe that the degree of entanglement increases with an increase in the photon number inside the cavity and a decrease in the dot-photon coupling. The behavior of the two-dot system, initially prepared in an entangled state and interacting with thermal light, is also studied.
The dynamical behaviors of the entanglement for the excitons in a system of two coupled quantum dots and a single-mode cavity field are investigated for two different initial conditions by means of the concurrence.It is shown that the direct coupling between the dots can reduce the degree of the entanglement for the excitons.For the initial cavity field being in the odd-coherent state,the degree of their entanglement decreases with the increase of the coherent intensity of cavity field.There is a trade-off for excitonic entanglement when cavity field is initially prepared in the even-coherent state.The relation between the average photon numbers of cavity field and quasi-maximally entangled excitonic coherent states is studied.
We study the relaxation dynamics of a quantum dot with local Coulomb correlations coupled to two noninteracting leads which are held in grand-canonical equilibrium. Only charge degrees of freedom are considered and the dot is described by a model which in the scaling limit becomes equivalent to the interacting resonant level model. We examine the time evolution of the current and the dot occupancy resulting from changes in the dot-lead coupling, the dots' on-site energy, or the charging energy. Abrupt and smooth parameter changes as well as setups with and without driving bias voltage are considered. For biased dots, we investigate the often studied response after turning on the dot-lead coupling but also the experimentally more relevant case in which the voltage is turned on. We identify and explain a variety of interesting many-body effects, and we clarify the role of initial correlations.
We investigate the entanglement between the spins of two quantum dots that are not connected at once to the same system. Quantum entanglement between localized spins is an essential property for the development of quantum computing and quantum information. It is for this reason that generating and controlling an entangled state between quantum dots received great attention in the later years. In this work, we show that the information on the spin orientation of a quantum dot can be kept, using the Kondo entanglement, in a reservoir of electrons. Then, this information can be transmitted to another dot after the first dot has been uncoupled from the reservoirs. We use a double quantum dot system in a parallel geometry to construct the initial state, where each dot interacts with reservoirs of different symmetries. We chose a phase in the couplings to induce an antiferromagnetic spin correlation between the dots. The time evolution of the initial state has been analyzed using the time-dependent density matrix renormalization group method. We found that a partially entangled state between the dots can be obtained, even if they are not connected at the same time. This entangled state is formed just during the transient and is destroyed in the stationary state. The stability of the state found in the transient is shown. To understand the details of these phenomena, a canonical transformation of the real space is used.
In this paper, we explore the dynamics of quantum correlations in an isolated physical quantum dot under the influence of intrinsic decoherence (ID). We characterize quantum correlations in the quantum dot system using Concurrence to capture the amount of entanglement, and we use Trace Distance Discord (TDD) and Local Quantum Uncertainty (LQU) to measure nonclassical correlations. Likewise, we investigate the effect of ID on the temporal evolution of these quantifiers. In particular, the behavior of the two discord-like quantifiers in terms of the system parameters and the ID rate is investigated and analyzed in detail. We found that TDD and LQU behave similarly for different parameters characterizing the considered system and that TDD is more resistant than Concurrence and LQU against the ID effects. Our results also show that the robustness of quantum correlations can be modulated by adjusting the ID rate, quantum dot physical properties and initial conditions.