Neerav Kharche

Magnetic field dependence of valley-splitting in miscut (100) SiGe/Si/SiGe quantum wells

Magnetic field dependence of valley-splitting in miscut (100) SiGe/Si/SiGe quantum wells Neerav Kharche, Marta Prada, Timothy Boykin, Gerhard Klimeck

Objective:

  • Explain experimentally observed suppression in valley-splitting in miscut (100) Si QWs
  • Study effect of alloy disorder and step roughness at Si/SiGe interface on the electronic structure

Approach:

  • Model miscut Si QWs along with SiGe buffers to include strain and atomistic alloy disorder in SiGe buffer
  • Strain relaxation: VFF-Keating
  • Magnetic field: Peierl’s substitution
  • Step roughness: replicate experimentally observed surface morphology on the atomistic grid

Impact:

  • Alloy disorder in SiGe and step roughness at Si/SiGe interface is crucial to accurately model valley-splitting
  • Model predicts experimentally observed valley-splitting without any ad-hoc fitting parameters
  • Publication [J79]

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