1303.2252 (Laura Cano-Cortés et al.)

The fundamental differences between Quantum Spin Hall edge-states at
zig-zag and armchair terminations of honeycomb and ruby nets    [PDF]

Laura Cano-Cortés, Carmine Ortix, Jeroen van den Brink

Combining an analytical and numerical approach we investigate the dispersion of the topologically protected spin-filtered edge-states of the Quantum Spin Hall state on honeycomb and ruby nets with zigzag (ZZ) and armchair (AC) edges. We show that the Fermi velocity of the helical edge-states on ZZ edges increases linearly with the strength of the spin-orbit coupling (SOC) whereas for AC edges the Fermi velocity is independent of the SOC. Also the decay length of edge states into the bulk is dramatically different for AC and ZZ edges, displaying an inverse functional dependence on the SOC.

View original: http://arxiv.org/abs/1303.2252