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Valley splitting in Si quantum dots embedded in SiGe
Birck and NCN Publications
  • S Srinivasan, Purdue University
  • Gerhard Klimeck, Network for Computational Nanotechnology, Birck Nanotechnology Center, Purdue University
  • Leonid P Rokhinson, Birck Nanotechnology Center, Purdue University
Abstract

We examine energy spectra of Si quantum dots embedded in Si0.75Ge0.25 buffers using atomistic numerical calculations for dimensions relevant to qubit implementations. The valley degeneracy of the lowest orbital state is lifted and valley splitting fluctuates with monolayer frequency as a function of the dot thickness. For dot thicknesses <= 6 nm, valley splitting is found to be > 150 mu eV. Using the unique advantage of atomistic calculations, we analyze the effect of buffer disorder on valley splitting. Disorder in the buffer leads to the suppression of valley splitting by a factor of 2.5; the splitting fluctuates with approximate to 20 mu eV for different disorder realizations. Through these simulations we can guide future experiments into regions of low device-to-device fluctuations. (C) 2008 American Institute of Physics.

Date of this Version
9-15-2008
Citation
APPLIED PHYSICS LETTERS 93, 112102, 2008
Citation Information
S Srinivasan, Gerhard Klimeck and Leonid P Rokhinson. "Valley splitting in Si quantum dots embedded in SiGe" (2008)
Available at: http://works.bepress.com/gerhard_klimeck/26/