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:cond-mat/0609217 · AIP conference proceedings

Spin Dynamics of Electron Nuclei Coupled System in a Double Quantum Dot

Özgür Çakır, T. Takagahara

Published Jan 1, 2007• 1 citation
arXivHTMLPDF

Abstract

Electron‐nuclei coupled system in a double quantum dot is studied. As a manifestation of quantum nature of nuclear spins, bunching of results of electron spin measurements, and revivals in the conditional probabilities are predicted. The underlying mechanism is the correlations between successive measurements induced via the nuclear spins. The electron spin coherence time can be extended via conditional measurements.

DOI
10.1063/1.2730284

Related papers

Electron spin dynamics and hyperfine interaction in coupled quantum dots

Özgür Çakır, T. Takagahara

We have investigated the quantum dynamics of the electron-nuclei coupled system in a double quantum dot and discovered a couple of new phenomena related to the quantum nature of nuclear spin system. Especially, the bunching of results of the electron spin measurements and the revival in the conditional probabilities are salient features of quantum dynamics. The underlying mechanism is the squeezing of the nuclear spin state through the electron spin measurements. This squeezing is expected to lead to the elongation of the electron spin coherence time. (© 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•Dec 1, 2006•2 citations

Quantum dynamics in electron-nuclei coupled spin system in quantum dots: Bunching, revival, and quantum correlation in electron-spin measurements

Özgür Çakır, T. Takagahara

We investigate quantum dynamics in the electron-nuclei coupled spin system in quantum dots and clarify the fundamental features of quantum correlation induced via successive electron-spin measurements. This quantum correlation leads to interesting phenomena such as the bunching of outcomes in the electron-spin measurements and the revival of an arbitrary initial electron-spin state. The nuclear spin system is also affected by the quantum correlation and is, in fact, squeezed via conditional measurements or postselection. This squeezing is confirmed by calculating the increase in the purity of the nuclear spin system. Thus, the successive electron-spin measurements provide a probabilistic method to squeeze the nuclear spin system. These new features are predicted not only for the case of double quantum dots occupied by a pair of electrons but also for the case of a single quantum dot occupied by a single electron or a pair of electrons.

arXiv:0801.1723•Physical Review B•Mar 4, 2008•6 citations

Estimation of nuclear spin state in a double quantum dot via hyperfine interaction

Özgür Çakır, T. Takagahara

Hyperfine interaction of electron spins with nuclear spins, in coupled double quantum dots is studied. Results of successive electron spin measurements exhibit bunching due to correlations induced via the nuclear spins. Further nuclear spins can be purified via conditional electron spin measurements which lead to electron spin revivals in the conditional probabilities. The electron spin coherence time can be extended via conditional measurements. The results are extended to a single electron on a single QD.

Journal of Physics Conference Series•Mar 1, 2007•0 citations

Theoretical aspects of quantum state transfer, correlation measurement and electron-nuclei coupled dynamics in quantum dots

T. Takagahara, Özgür Çakır

Photons and electrons are the key quantum media for the quantum information processing based on solid state devices. The essential ingredients to accomplish the quantum repeater were investigated and their underlying physics were revealed. The relevant elementary processes of the quantum state transfer between a single photon and a single electron were analyzed, to clarify the conditions to be satisfied to achieve the high fidelity of the quantum state transfer. An optical method based on the Faraday rotation was proposed to carry out the Bell measurement of two electrons which is a key operation in the entanglement swapping for the quantum repeater and its feasibility was confirmed. Also investigated was the quantum dynamics in the electron-nuclei coupled spin system in quantum dots and a couple of new phenomena were predicted related to the correlations induced by the hyperfine interaction, namely, bunching and revival in the electron spin measurements. These findings will pave the way to accomplish the efficient and robust quantum repeater and nuclear spin quantum memory.

arXiv:0801.1871•Journal of Nanophotonics•Dec 1, 2007•3 citations

Spin dynamics at the singlet–triplet crossings in a double quantum dot

J Särkkä, Ari Harju

We simulate the control of the spin states in a two-electron double quantum dot when an external detuning potential is used to pass the system through an anticrossing. The hyperfine coupling of the electron spins with the surrounding nuclei causes not only anticrossing of the spin states but also decoherence of the spin states. We calculate numerically the singlet–triplet decoherence for different detuning values and find good agreement with the experimental measurement results for a similar setup. We predict an interference effect due to the coupling of the T 0 and T + states.

arXiv:1007.0080•New Journal of Physics•Apr 8, 2011•13 citations

CONTROL OF ELECTRON SPIN DECOHERENCE IN MESOSCOPIC NUCLEAR SPIN BATHS

Ren‐Bao Liu, Wang Yao, Lu Jeu Sham

The electron spin decoherence by nuclear spins in semiconductor quantum dots is caused by quantum entanglement between the electron and the nuclei. The many-body dynamics problem of the interacting nuclear spins can be solved with the pair-correlation approximation which treats the nuclear spin flip-flops as mutually independent. The nuclear spin dynamics can be controlled by simply flipping the electron spin so that the electron is disentangled from the nuclei and hence its lost coherence is restored.

International Journal of Modern Physics B•Jan 20, 2008•1 citation
Electron‐nuclei coupled system in a double quantum dot is studied. As a manifestation of quantum nature of nuclear spins, bunching of results of electron spin measurements, and revivals in the conditional probabilities are predicted. The underlying mechanism is the correlations between successive measurements induced via the nuclear spins. The electron spin coherence time can be extended via conditional measurements.
We have investigated the quantum dynamics of the electron-nuclei coupled system in a double quantum dot and discovered a couple of new phenomena related to the quantum nature of nuclear spin system. Especially, the bunching of results of the electron spin measurements and the revival in the conditional probabilities are salient features of quantum dynamics. The underlying mechanism is the squeezing of the nuclear spin state through the electron spin measurements. This squeezing is expected to lead to the elongation of the electron spin coherence time. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
We investigate quantum dynamics in the electron-nuclei coupled spin system in quantum dots and clarify the fundamental features of quantum correlation induced via successive electron-spin measurements. This quantum correlation leads to interesting phenomena such as the bunching of outcomes in the electron-spin measurements and the revival of an arbitrary initial electron-spin state. The nuclear spin system is also affected by the quantum correlation and is, in fact, squeezed via conditional measurements or postselection. This squeezing is confirmed by calculating the increase in the purity of the nuclear spin system. Thus, the successive electron-spin measurements provide a probabilistic method to squeeze the nuclear spin system. These new features are predicted not only for the case of double quantum dots occupied by a pair of electrons but also for the case of a single quantum dot occupied by a single electron or a pair of electrons.
Hyperfine interaction of electron spins with nuclear spins, in coupled double quantum dots is studied. Results of successive electron spin measurements exhibit bunching due to correlations induced via the nuclear spins. Further nuclear spins can be purified via conditional electron spin measurements which lead to electron spin revivals in the conditional probabilities. The electron spin coherence time can be extended via conditional measurements. The results are extended to a single electron on a single QD.
Photons and electrons are the key quantum media for the quantum information processing based on solid state devices. The essential ingredients to accomplish the quantum repeater were investigated and their underlying physics were revealed. The relevant elementary processes of the quantum state transfer between a single photon and a single electron were analyzed, to clarify the conditions to be satisfied to achieve the high fidelity of the quantum state transfer. An optical method based on the Faraday rotation was proposed to carry out the Bell measurement of two electrons which is a key operation in the entanglement swapping for the quantum repeater and its feasibility was confirmed. Also investigated was the quantum dynamics in the electron-nuclei coupled spin system in quantum dots and a couple of new phenomena were predicted related to the correlations induced by the hyperfine interaction, namely, bunching and revival in the electron spin measurements. These findings will pave the way to accomplish the efficient and robust quantum repeater and nuclear spin quantum memory.
We simulate the control of the spin states in a two-electron double quantum dot when an external detuning potential is used to pass the system through an anticrossing. The hyperfine coupling of the electron spins with the surrounding nuclei causes not only anticrossing of the spin states but also decoherence of the spin states. We calculate numerically the singlet–triplet decoherence for different detuning values and find good agreement with the experimental measurement results for a similar setup. We predict an interference effect due to the coupling of the T 0 and T + states.
The electron spin decoherence by nuclear spins in semiconductor quantum dots is caused by quantum entanglement between the electron and the nuclei. The many-body dynamics problem of the interacting nuclear spins can be solved with the pair-correlation approximation which treats the nuclear spin flip-flops as mutually independent. The nuclear spin dynamics can be controlled by simply flipping the electron spin so that the electron is disentangled from the nuclei and hence its lost coherence is restored.