Adiabatic quantum pumping in buckled graphene nanoribbon driven by a kink

Abstract

We propose a new type of quantum pump in buckled graphene nanoribbon, adiabatically driven by a kink moving along the ribbon. From a practical point of view, pumps with moving scatterers present advantages as compared to gate-driven pumps, like enhanced charge transfer per cycle per channel. The kink geometry is simplified by truncating the spatial arrangement of carbon atoms with the classical φ 4 model solution, including a width renormalization following from the Su-Schrieffer-Heeger model for carbon nanostructures. We demonstrate numerically, as a proof of concept, that for moderate deformations a stationary kink at the ribbon center may block the current driven by the external voltage bias. In the absence of a bias, a moving kink leads to highly-effective pump effect, with a charge per unit cycle dependent on the gate voltage.

Adiabatic pumping driven by moving kink and quantum standard ampere in buckled graphene nanoribbon

“…Earlier [15], we have shown that the system similar to the presented in Fig. 1 consisting of metallic graphene nanoribbon with armchair edges coupled to heavily-doped graphene leads may operate as efficient quantum pump, but the charge per cycle is not quantized.…”

“…In attempt to improve electromechanical characteristics of such devices, one need to address fundamental issues concerning the structure of effective Hamiltonian at nanoscale, including tight-binding parameters [3], elastic coefficients [4,5], and electron phononcoupling [6]. Numerous works have addressed the idea of quantum pumping in graphene nanostructures [7][8][9][10][11][12][13][14][15], employing various physical mechanisms. These include gatedriven pumping [7,8], laser light [9], strain-induced fields [10], tunable magnetoresistance [11], quantum Hall states [12], but also electromechanical effects accompanying sliding Moiré patterns in twisted bilayer [13,14], or (most recently) moving kink in buckled graphene nanoribbon [15].…”

“…Numerous works have addressed the idea of quantum pumping in graphene nanostructures [7][8][9][10][11][12][13][14][15], employing various physical mechanisms. These include gatedriven pumping [7,8], laser light [9], strain-induced fields [10], tunable magnetoresistance [11], quantum Hall states [12], but also electromechanical effects accompanying sliding Moiré patterns in twisted bilayer [13,14], or (most recently) moving kink in buckled graphene nanoribbon [15].…”