Edge states interferometry and spin rotations in zigzag graphene nanoribbons

An interesting property of zigzag graphene nanoribbons is the presence of edge states, extended along its borders but localized in the transverse direction. Here we show that because of this property, electron transport through an externally induced potential well displays two-path-interference oscillations when subjected either to a magnetic or a transverse electric field. This effect does not require the existence of an actual hole in the nanoribbon's geometry. Moreover, since edge states are spin polarized, having opposite polarization on opposite sides, such interference effect can be used to rotate the spin of the incident carriers in a controlled way.