Adiabatic quantum pump in a zigzag graphene nanoribbon junction*
Zhang Lin
       
Energy–momentum dispersion of zero-energy edge states of the left (p-doped), C (un-doped), and right (n-doped) ZGNRs in the p–n junction. The “+(−)” represents the even (odd) pseudo-parity of the edge mode, and it could be different for the conduction band (solid line) and the valence band (dashed line). The arrows show the electron transport owing to the valley selection rule. The shaded areas around ± U are two pumping regions for producing nonzero charge currents.