Figure 2: Curvature dependent spin conductances of QSH ribbons.
From: Bending strain engineering in quantum spin hall system for controlling spin currents
(a–c) Schematic diagrams of spin current and charge current flowing along the edges as the θe increases from 0° (a) to 180° (c). A pair of edge states counter propagate along all four edges subject to TRS. The spins rotate adiabatically along the curved edges. The highlight of spin directions at the two opposite edges under the same charge current flow direction +kx is shown in the bottom of a–c. (d) Calculated spin conductance 
for the QSH ribbons with different θe in a two-terminal device setting. (e) The values of 
in the QSH regime (plateau region) in d as a function of θe, which can be perfectly described by the equation of 
.
