Adiabatic pumping driven by a moving kink in a buckled graphene nanoribbon with implications for a quantum standard for the ampere
D Suszalski and A Rycerz, PHYSICAL REVIEW B, 102, 165408 (2020).
A quantum pump in a buckled graphene ribbon with armchair edges is discussed numerically. By solving the Su-Schrieffer-Heeger model and performing the computer simulation of quantum transport we find that a kink adiabatically moving along the metallic ribbon results in highly efficient pumping, with a charge per kink transition close to the maximal value determined by the Fermi velocity in graphene. Remarkably, insulating nanoribbon show the quantized value of a charge per kink (2e) in a relatively wide range of the system parameters, providing a candidate for the quantum standard ampere. We attribute it to the presence of a localized electronic state, moving together with a kink, whose energy lies within the ribbon energy gap.
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