Fingerprint of Different Spin-Orbit Terms for Spin Transport in HgTe Quantum Wells
| Autor: | Rothe, D. G., Reinthaler, R. W., Liu, C. -X., Molenkamp, L. W., Zhang, S. -C., Hankiewicz, E. M. |
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| Rok vydání: | 2010 |
| Předmět: | |
| Zdroj: | New J. Phys. 12 065012 (2010) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/1367-2630/12/6/065012 |
| Popis: | Using $\vec{k}$$\cdot$$\vec{p}$ theory, we derive an effective four band model describing the physics of the typical two-dimensional topological insulator (HgTe/CdTe quantum well) in the presence of out-of-plane in z-direction inversion breaking and in-plane confining potentials. We find that up to third order in perturbation theory, only the inversion breaking potential generates new elements to the four band Hamiltonian that are off-diagonal in spin space. When this new effective Hamiltonian is folded into an effective two band model for the conduction (electron) or valence (heavy hole) bands, two competing terms appear: (1) a Rashba spin-orbit interaction originating from inversion breaking potential in z-direction and (2) an in-plane Pauli term as a consequence of the in-plane confining potential. Spin transport in the conduction band is further analysed within the Landauer-B\"uttiker formalism. We find that for asymmetrically doped HgTe quantum wells, the behaviour of the spin-Hall conductance is dominated by the Rashba term. Comment: 23 pages, 4 figures, submitted to special NJP issue "Focus on topological insulators" |
| Databáze: | arXiv |
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