Spectroscopy of a few-electron single-crystal silicon quantum dot

ORAL

Abstract

We report measurements and theoretical simulations of a few-electron quantum dot formed by atomically patterned doping in a P:Si $\delta$-layer. The device is embedded entirely within epitaxial Si, including source-drain tunnel leads and capacitive side-gates. Coulomb blockade and excited state resonances are observed, and we discuss these excited states in the context of calculated multi-electron levels on the dot and van Hove singularities in the leads. The atomically abrupt confinement potential causes a large valley splitting of states within the $\Gamma$ band, as appropriate for spin quantum computing. The sharp lateral confinement in the dot, with radius $<2$~nm, leads to novel effects associated with valley splitting in the $\Delta$ band.

*This work was supported by ARO, LPS, and NSF.

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Authors

  • Mark Friesen

    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Martin Fuechsle

    • University of New South Wales

  • S. Mahapatra

    • Australian Research Council Centre of Excellence for Quantum Computer Technology, University of New South Wales, Sydney NSW 2052, Australia
    • University of New South Wales

  • F. A. Zwanenburg

    • University of New South Wales

  • M. A. Eriksson

    • University of Wisconsin Madison
    • University of Wisconsin-Madison
    • Department of Physics, University of Wisconsin-Madison
    • University of Wisconsin - Madison

  • Michelle Y. Simmons

    • University of New South Wales