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

International Conference on Quantum Information

Pure dephasing dynamics of two charge qubits

W. Ben Chouikha, S. Jaziri, R. Bennaceur

Published Jan 1, 2011• 0 citations
Publisher

Abstract

We study the effect of pure dephasing on the entanglement of two charge qubits. The pure dephasing is due to the dephasing between two states of two electrons confined in double quantum dot (no relaxation). We evaluate the concurrence in order to quantify the evolution of the degree of entanglement. We show that the pure dephasing due to the interaction with acoustic phonons led to complete disentanglement.

DOI
10.1364/icqi.2011.qmi41

Related papers

Decoherence dynamics of two charge qubits in vertically coupled quantum dots

W. Ben Chouikha, S. Jaziri, R. Bennaceur

The decoherence dynamics of two charge qubits in a double quantum dot is investigated theoretically. We consider the quantum dynamics of two interacting electrons in a vertically coupled quantum dot driven by an external electric field. We derive the equations of motion for the density matrix, in which the presence of an electron confined in the double dot represents one qubit. A Markovian approach to the dynamical evolution of the reduced density matrix is adopted. We evaluate the concurrence of two qubits in order to study the effect of acoustic phonons on the entanglement. We also show that the disentanglement effect depends on the double dot parameters and increases with the temperature.

Physical Review A•Dec 7, 2007•4 citations

Pure dephasing of two charge qubits in coupled quantum dots

W. Ben Chouikha, S. Jaziri, R. Bennaceur

Abstract We study the pure dephasing of two electrons confined in vertically coupled quantum dots, in which the presence of one electron confined in the double dot represents one qubit. We numerically evaluated the dephasing rates due to electrons coupling to both acoustic and optical phonons. Our numerically results show that the pure dephasing rates dependent on the separation between dots and the strength of electrons confinement. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Physica status solidi. C, Conferences and critical reviews/Physica status solidi. C, Current topics in solid state physics•Nov 22, 2006•0 citations

Complete disentanglement by partial pure dephasing

Katarzyna Roszak, Paweł Machnikowski

We study the effect of pure dephasing on the entanglement of a pair of two-level subsystems (qubits). We show that partial dephasing induced by a super-Ohmic reservoir, corresponding to well-established properties of confined charge states and phonons in semiconductors, may lead to complete disentanglement. We show also that the disentanglement effect increases with growing distance between the two subsystems.

arXiv:quant-ph/0507027•Physical Review A•Feb 6, 2006•102 citations

Telegraph noise effects on two charge qubits in double quantum dots

A. Ayachi, W. Ben Chouikha, S. Jaziri +1 more

We analyze theoretically the decoherence of two interacting electrons in a double self-assembled quantum dot due to a random telegraph noise. For this purpose we have examined the pure dephasing rate by evaluating the decoherence factor. The latter has been shown to be different from that calculated within the Gaussian approximation in the strong coupling regime. In order to determine the influence of the random telegraph noise on the entanglement of the system states, the concurrence, the populations, and the entropy are evaluated as well. Our results show that telegraph noise can severely impact the coherence of charge qubits.

arXiv:1312.0427•Physical Review A•Jan 27, 2014•16 citations

Pure dephasing of double-quantum-dot charge qubits in freestanding slabs

Ying-Yen Liao, Y. N. Chen

We study phonon-induced pure dephasing in a double-quantum-dot qubit that is embedded in a freestanding slab. The dispersion relations are evaluated to probe the phonon characteristics of the slab. The pure dephasing factor in the off-diagonal elements of the density matrix is calculated. Numerical results demonstrate that time evolution of this factor exhibits a nonmonotonic feature, resulting from the phonon confinement effect. Significant contribution from individual phonon mode is analyzed in detail. We also study effects of temperature and double-dot position on the pure dephasing. In particular, two remarkable oscillations are observed due to phonon van Hove singularities.

Physical Review B•Apr 1, 2010•7 citations

Complete and Partial Loss of Entanglement Due to a Phonon-Assisted Dephasing Process

Katarzyna Roszak, Paweł Machnikowski, Lucjan Jacak

We study the evolution of entanglement between two excitons in a double quantum dot system coupled to a super-Ohmic reservoir.As expected entanglement is more fragile than local coherence, but, surprisingly, for a set of pure states disentanglement can be complete in a finite time under conditions that lead to the usual partial pure-dephasing.

Acta Physica Polonica A•Sep 1, 2006•1 citation
We study the effect of pure dephasing on the entanglement of two charge qubits. The pure dephasing is due to the dephasing between two states of two electrons confined in double quantum dot (no relaxation). We evaluate the concurrence in order to quantify the evolution of the degree of entanglement. We show that the pure dephasing due to the interaction with acoustic phonons led to complete disentanglement.
The decoherence dynamics of two charge qubits in a double quantum dot is investigated theoretically. We consider the quantum dynamics of two interacting electrons in a vertically coupled quantum dot driven by an external electric field. We derive the equations of motion for the density matrix, in which the presence of an electron confined in the double dot represents one qubit. A Markovian approach to the dynamical evolution of the reduced density matrix is adopted. We evaluate the concurrence of two qubits in order to study the effect of acoustic phonons on the entanglement. We also show that the disentanglement effect depends on the double dot parameters and increases with the temperature.
We analyze theoretically the decoherence of two interacting electrons in a double self-assembled quantum dot due to a random telegraph noise. For this purpose we have examined the pure dephasing rate by evaluating the decoherence factor. The latter has been shown to be different from that calculated within the Gaussian approximation in the strong coupling regime. In order to determine the influence of the random telegraph noise on the entanglement of the system states, the concurrence, the populations, and the entropy are evaluated as well. Our results show that telegraph noise can severely impact the coherence of charge qubits.
We study phonon-induced pure dephasing in a double-quantum-dot qubit that is embedded in a freestanding slab. The dispersion relations are evaluated to probe the phonon characteristics of the slab. The pure dephasing factor in the off-diagonal elements of the density matrix is calculated. Numerical results demonstrate that time evolution of this factor exhibits a nonmonotonic feature, resulting from the phonon confinement effect. Significant contribution from individual phonon mode is analyzed in detail. We also study effects of temperature and double-dot position on the pure dephasing. In particular, two remarkable oscillations are observed due to phonon van Hove singularities.