Semiconductor quantum dots for electron spin qubits

W.G. van der Wiel, M. Stopa, T. Kodera, T. Hatano, S. Tarucha

    Research output: Contribution to journalArticleAcademicpeer-review

    24 Citations (Scopus)
    91 Downloads (Pure)

    Abstract

    We report on our recent progress in applying semiconductor quantum dots for spin-based quantum computation, as proposed by Loss and DiVincenzo (1998 Phys. Rev. A 57 120). For the purpose of single-electron spin resonance, we study different types of single quantum dot devices that are designed for the generation of a local ac magnetic field in the vicinity of the dot. We observe photon-assisted tunnelling as well as pumping due to the ac voltage induced by the ac current driven through a wire in the vicinity of the dot, but no evidence for ESR so far. Analogue concepts for a double quantum dot and the hydrogen molecule are discussed in detail. Our experimental results in laterally coupled vertical double quantum dot device show that the Heitler–London model forms a good approximation of the two-electron wavefunction. The exchange coupling constant J is estimated. The relevance of this system for two-qubit gates, in particular the SWAP operation, is discussed. Density functional calculations reveal the importance of the gate electrode geometry in lateral quantum dots for the tunability of J in realistic two-qubit gates.
    Original languageEnglish
    Article number28
    Number of pages26
    JournalNew journal of physics
    Volume8
    Issue numberIEEE Produ/28
    DOIs
    Publication statusPublished - 3 Feb 2006

    Keywords

    • IR-59279
    • METIS-238792
    • EWI-9469

    Fingerprint Dive into the research topics of 'Semiconductor quantum dots for electron spin qubits'. Together they form a unique fingerprint.

  • Cite this