Numerical simulation of spin-qubit operation in coupled quantum dots

Daisuke Goto, Mikio Eto

Research output: Contribution to journalConference article

Abstract

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.

Original languageEnglish
Pages (from-to)554-556
Number of pages3
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume4
Issue number2
DOIs
Publication statusPublished - 2007 Dec 1
EventInternational Conference on Superlattices, Nano-structures and Nano-devices, ICSNN-2006 - Istanbul, Turkey
Duration: 2006 Jul 302006 Aug 4

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ASJC Scopus subject areas

  • Condensed Matter Physics

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