SP3S* + Spin-Orbit Model
Basis
20-band model that doubles the SP3S* basis with explicit spin:
| Index 1-10 | Spin-up | Index 11-20 | Spin-down |
|---|---|---|---|
| $s, p_x, p_y, p_z, s^*$ (anion) | $\uparrow$ | $s, p_x, p_y, p_z, s^*$ (anion) | $\downarrow$ |
| $s, p_x, p_y, p_z, s^*$ (cation) | $\uparrow$ | $s, p_x, p_y, p_z, s^*$ (cation) | $\downarrow$ |
Spin-Orbit Coupling
Spin-orbit interaction is added as an on-site coupling between p orbitals of different spin. The spin-orbit splitting parameter Δ controls the strength of the coupling.
Available Parameter Sources
| Source | Materials |
|---|---|
Vogl1983 | Si, Ge, C, Sn, SiC, GaAs, GaP, GaSb, AlAs, AlP, AlSb, InAs, InP, InSb, ZnSe, ZnTe |
Klimeck2000 | GaAs, GaP, GaSb, AlAs, AlP, AlSb, InAs, InP, InSb |
When to Use
Required for materials with significant spin-orbit splitting, such as InSb, GaSb, and other heavy-element semiconductors where the split-off band energy is important.
Reference
- G. Klimeck, R.C. Bowen, T.B. Boykin, T.A. Cwik, "sp3s* tight-binding parameters for transport simulations in compound semiconductors," Superlattices and Microstructures 27, 519 (2000). DOI:10.1006/spmi.2000.0862