Numerical simulation of spin-qubit operation in coupled quantum dots

Daisuke Goto, Mikio Eto

研究成果: Article

抄録

Electronic states and spin operation in coupled quantum dots are numerically studied, considering realistic shape of quantum dots and electron-electron interaction, (i) We evaluate the spin coupling J between two electron spins, as a function of magnetic field perpendicular to the quantum dots. We observe a transition from antiferromagnetic coupling (J > 0) to ferromagnetic coupling (J < 0) at magnetic field of a few Tesla. The spin coupling is hardly influenced by the size difference between the quantum dots if the energy levels are matched, (ii) We simulate SWAP gate operations by calculating the time development of two electron spins. We show that a sudden change of tunnel barrier may result in the gate errors. The spin exchange is incomplete in the presence of strong spin-orbit interaction in InGaAs.

元の言語English
ページ(範囲)554-556
ページ数3
ジャーナルPhysica Status Solidi (C) Current Topics in Solid State Physics
4
発行部数2
DOI
出版物ステータスPublished - 2007

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quantum dots
electron spin
simulation
spin exchange
spin-orbit interactions
magnetic fields
tunnels
electron scattering
energy levels
electronics
electrons

ASJC Scopus subject areas

  • Condensed Matter Physics

これを引用

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AB - Electronic states and spin operation in coupled quantum dots are numerically studied, considering realistic shape of quantum dots and electron-electron interaction, (i) We evaluate the spin coupling J between two electron spins, as a function of magnetic field perpendicular to the quantum dots. We observe a transition from antiferromagnetic coupling (J > 0) to ferromagnetic coupling (J < 0) at magnetic field of a few Tesla. The spin coupling is hardly influenced by the size difference between the quantum dots if the energy levels are matched, (ii) We simulate SWAP gate operations by calculating the time development of two electron spins. We show that a sudden change of tunnel barrier may result in the gate errors. The spin exchange is incomplete in the presence of strong spin-orbit interaction in InGaAs.

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