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arXiv · 0908.2417

Spin-orbit splittings in Si/SiGe quantum wells

M. Prada·G. Klimeck·R. Joynt
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Abstract

We present a calculation of the wavevector-dependent subband level splitting from spin-orbit coupling in Si/SiGe quantum wells. We first use the effective-mass approach, where the splittings are parameterized by separating contributions from the Rashba and Dresselhaus terms. We then determine the parameters by fitting tight-binding numerical results obtained using the quantitative nanoelectronic modeling tool, NEMO-3D. We describe the relevant parameters as a function of applied electric field and well width in our numerical simulations. For a silicon membrane, we find the bulk Rashba parameter to be linear in field, $α= α^1E_z$ with $α^1 \simeq 2\times$ 10 $^{-5}$nm$^{-2}$. The dominant contribution to the spin-orbit splitting is from Dresselhaus-type terms, and the magnitude for a typical flat SiGe/Si/SiGe quantum well can be as high as 1$μ$eV.

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M. Prada, G. Klimeck, R. Joynt. 2009-08-17. Spin-orbit splittings in Si/SiGe quantum wells. https://arxiv.org/abs/0908.2417

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