TY  - JOUR
A1  - Rothe, D. G.
A1  - Reinthaler, R. W.
A1  - Liu, C-X
A1  - Molenkamp, L. W.
A1  - Zhang, S-C
A1  - Hankiewicz, E. M.
T1  - Fingerprint of different spin-orbit terms for spin transport in HgTe quantum wells
N2  - Using k · p theory, we derive an effective four-band model describing the physics of the typical two-dimensional topological insulator (HgTe/CdTe quantum well (QW)) in the presence of an out-of-plane (in the z-direction) inversion breaking potential and an in-plane potential. 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 twoband model for the conduction (electron) or valence (heavy hole) bands, two competing terms appear: (i) a Rashba spin–orbit interaction originating from inversion breaking potential in the z-direction and (ii) an in-plane Pauli term as a consequence of the in-plane potential. Spin transport in the conduction band is further analysed within the Landauer–Büttiker formalism. We find that for asymmetrically doped HgTe QWs, the behaviour of the spin-Hall conductance is dominated by the Rashba term.
KW  - Physik
Y1  - 2010
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68362
ER  -