Valley splitting in an n-channel (100) inversion layer on p-type silicon

Abstract

The extended zone effective mass theory is proposed and is applied to the investigation of the valley splitting in an n-channel (100)Si inversion layer. The splitting is due to a tunnelling effect in k-space, and is given approximately as ΔE ≈ 0.15 ( N inv + g −1 N depl) meV ( N inv and N depl in units of 10 12 cm −2 g = 11 32 ). When the strain exists, or when k x and k y are both non-zero, the splitting is a little larger than this value. The enhancements of the Zeeman splittings and the valley splittings caused by the many body effects under strong magnetic fields are taken into account. The theory predicts the structure and line shape of the transverse magnetoconductivity oscillations, and the results show a very good agreement with the experiment including the cusps at the peak of the Landau levels in the indices N ⩾ 3.