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

Journal of Physics Conference Series

An orbital entanglement in two-electron quantum dots in a magnetic field

A. Yu. Chizhov, R. G. Nazmitdinov

Published Nov 1, 2010• 1 citation
Publisher

Abstract

We consider a simple model for two-electron quantum dots (QDs) in the perpendicular magnetic field. With the aid of this model we study the degree of the orbital entanglement as a function of the magnetic field strength and the QD shape. We found that the circular QD exhibits no entanglement in the magnetic field. Although the entanglement increases with the increase of the QD deformation at a fixed value of the magnetic field, it approaches the constant value at the fixed deformation with the increase of the magnetic field.

DOI
10.1088/1742-6596/248/1/012021

Related papers

Orbital entanglement in an exactly solvable two-electron quantum dot model

Alexei Vladimirovich Chizhov, R. G. Nazmitdinov

We consider an exactly solvable two-dimensional model of a two-electron parabolic quantum dot (QD) under the perpendicular magnetic field. We perform a detailed study of the degree of the orbital entanglement of the ground and first excited singlet state depending on the shape of QD, the strength of the effective interaction and the magnetic field. It was found that a degree of entanglement increases with the growth of interaction between electrons. The magnetic field destroys the entanglement of electrons. However, the entanglement in deformed QDs is more stable to the effect of the magnetic field.

Journal of Physics Conference Series•Feb 8, 2012•2 citations

Quantum entanglement in a two-electron quantum dot in magnetic field

R. G. Nazmitdinov, Alexei Vladimirovich Chizhov

The properties of quantum entanglement of the ground state in an exactly solvable model of a two-electron QD have been investigated. It is shown that the degree of entanglement increases with enhancement of interaction between electrons, irrespective of the shape of electron confining potential in a QD. A magnetic field destroys electron entanglement. However, the entanglement in deformed QDs is more stable against magnetic field.

Optics and Spectroscopy•Mar 1, 2012•4 citations

Magnetic alteration of entanglement in two-electron quantum dots

N. S. Simonović, R. G. Nazmitdinov

Quantum entanglement is analyzed thoroughly in the case of the ground and lowest states of two-electron axially symmetric quantum dots under a perpendicular magnetic field. The individual-particle and the center-of-mass representations are used to study the entanglement variation at the transition from interacting to noninteracting particle regimes. The mechanism of symmetry breaking due to the interaction, which results in the states with symmetries related to the latter representation only being entangled even at the vanishing interaction, is discussed. The analytical expression for the entanglement measure based on the linear entropy is derived in the limit of noninteracting electrons. It reproduces remarkably well the numerical results for the lowest states with the magnetic quantum number $M\ensuremath{\ge}2$ in the interacting regime. It is found that the entanglement of the ground state is a discontinuous function of the field strength. A method to estimate the entanglement of the ground state, characterized by the quantum number $M$, with the aid of the magnetic-field dependence of the addition energy is proposed.

arXiv:1511.09094•Physical Review A•Nov 24, 2015•17 citations

Entanglement of electron orbital motion in open two-electron quantum dots

Alexei Vladimirovich Chizhov

In the present report, the effects of decoherence in a two-electron quantum dot coupled with its environment are investigated. Environmental effects on the quantum dynamics of electrons are modeled by coupling the dot with a thermo-bath at fixed temperatures. In such an approach, the special emphasis is placed on the analysis of the entanglement degradation of electron orbital motion depending on the quantum dot parameters (the strength of electron interaction and quantum dot shapes) and on the temperature of environment.

Journal of Physics Conference Series•Nov 26, 2012•2 citations

Entanglement dynamics of electron spins in quantum dots under a nonuniform magnetic field

Fengxue Zhou, Yihong Qi, Yueping Niu +3 more

We investigate entanglement of two coupled electron spins in quantum dots (QDs) in the presence of an inhomogeneous magnetic field. The important effects of the inhomogeneous field are discussed for the dynamics of entanglement. Due to the system’s symmetry, the inhomogeneity of the field is shown not to affect the evolution of entanglement for Φ-type Bell state while it plays a key role for Ψ-type Bell state. For the maximal entangled Bell states, the field is positive for the entanglement dynamics. The mean field can increase the entanglement revival for Φ-type Bell state while an inhomogeneous field can promote the entanglement revival for Ψ-type Bell state. For the unentangled initial states, the field is destructive for the entanglement generation induced by the coupling of the two spins.

Journal of the Korean Physical Society•Apr 1, 2012•0 citations

Three-electron anisotropic quantum dots in variable magnetic fields: Exact results for excitation spectra, spin structures, and entanglement

Yuesong Li, Constantine Yannouleas, Uzi Landman

Exact-diagonalization calculations for $N=3$ electrons in anisotropic quantum dots, covering a broad range of confinement anisotropies and strength of interelectron repulsion, are presented for zero and low magnetic fields. The excitation spectra are analyzed as a function of the strength of the magnetic field and for increasing quantum-dot anisotropy. Analysis of the intrinsic structure of the many-body wave functions through spin-resolved two-point correlations reveals that electrons tend to localize forming Wigner molecules. For certain ranges of dot parameters (mainly at strong anisotropy), the Wigner molecules acquire a linear geometry, and the associated wave functions with a spin projection ${S}_{z}=1∕2$ are similar to the representative class of strongly entangled states referred to as the $W$ states. For other ranges of parameters (mainly at intermediate anisotropy), the Wigner molecules exhibit a more complex structure consisting of two mirror isosceles triangles. This latter structure can be viewed as an embryonic unit of a zigzag Wigner crystal in quantum wires. The degree of entanglement in three-electron quantum dots can be quantified through the use of the von Neumann entropy.

arXiv:0710.4325•Physical Review B•Dec 11, 2007•37 citations
We consider a simple model for two-electron quantum dots (QDs) in the perpendicular magnetic field. With the aid of this model we study the degree of the orbital entanglement as a function of the magnetic field strength and the QD shape. We found that the circular QD exhibits no entanglement in the magnetic field. Although the entanglement increases with the increase of the QD deformation at a fixed value of the magnetic field, it approaches the constant value at the fixed deformation with the increase of the magnetic field.
We consider an exactly solvable two-dimensional model of a two-electron parabolic quantum dot (QD) under the perpendicular magnetic field. We perform a detailed study of the degree of the orbital entanglement of the ground and first excited singlet state depending on the shape of QD, the strength of the effective interaction and the magnetic field. It was found that a degree of entanglement increases with the growth of interaction between electrons. The magnetic field destroys the entanglement of electrons. However, the entanglement in deformed QDs is more stable to the effect of the magnetic field.
Quantum entanglement is analyzed thoroughly in the case of the ground and lowest states of two-electron axially symmetric quantum dots under a perpendicular magnetic field. The individual-particle and the center-of-mass representations are used to study the entanglement variation at the transition from interacting to noninteracting particle regimes. The mechanism of symmetry breaking due to the interaction, which results in the states with symmetries related to the latter representation only being entangled even at the vanishing interaction, is discussed. The analytical expression for the entanglement measure based on the linear entropy is derived in the limit of noninteracting electrons. It reproduces remarkably well the numerical results for the lowest states with the magnetic quantum number $M\ensuremath{\ge}2$ in the interacting regime. It is found that the entanglement of the ground state is a discontinuous function of the field strength. A method to estimate the entanglement of the ground state, characterized by the quantum number MMM, with the aid of the magnetic-field dependence of the addition energy is proposed.
In the present report, the effects of decoherence in a two-electron quantum dot coupled with its environment are investigated. Environmental effects on the quantum dynamics of electrons are modeled by coupling the dot with a thermo-bath at fixed temperatures. In such an approach, the special emphasis is placed on the analysis of the entanglement degradation of electron orbital motion depending on the quantum dot parameters (the strength of electron interaction and quantum dot shapes) and on the temperature of environment.
We investigate entanglement of two coupled electron spins in quantum dots (QDs) in the presence of an inhomogeneous magnetic field. The important effects of the inhomogeneous field are discussed for the dynamics of entanglement. Due to the system’s symmetry, the inhomogeneity of the field is shown not to affect the evolution of entanglement for Φ-type Bell state while it plays a key role for Ψ-type Bell state. For the maximal entangled Bell states, the field is positive for the entanglement dynamics. The mean field can increase the entanglement revival for Φ-type Bell state while an inhomogeneous field can promote the entanglement revival for Ψ-type Bell state. For the unentangled initial states, the field is destructive for the entanglement generation induced by the coupling of the two spins.
Exact-diagonalization calculations for N=3N=3N=3 electrons in anisotropic quantum dots, covering a broad range of confinement anisotropies and strength of interelectron repulsion, are presented for zero and low magnetic fields. The excitation spectra are analyzed as a function of the strength of the magnetic field and for increasing quantum-dot anisotropy. Analysis of the intrinsic structure of the many-body wave functions through spin-resolved two-point correlations reveals that electrons tend to localize forming Wigner molecules. For certain ranges of dot parameters (mainly at strong anisotropy), the Wigner molecules acquire a linear geometry, and the associated wave functions with a spin projection Sz=1∕2{S}_{z}=1∕2Sz​=1∕2 are similar to the representative class of strongly entangled states referred to as the WWW states. For other ranges of parameters (mainly at intermediate anisotropy), the Wigner molecules exhibit a more complex structure consisting of two mirror isosceles triangles. This latter structure can be viewed as an embryonic unit of a zigzag Wigner crystal in quantum wires. The degree of entanglement in three-electron quantum dots can be quantified through the use of the von Neumann entropy.