Single-Parameter Quantum Pumping in Graphene Nanoribbons with Staggered Sublattice Potential

• Published in: Chinese physics letters Vol. 34; no. 5; pp. 96 - 100
• Main Author: 李艳华 熊永建
• Format: Journal Article
• Language: English
• Published: 01.05.2017
• Subjects: 交错; 单参数; 格林函数方法; 电流方向; 石墨; 纳米带; 量子; 驱动频率
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/34/5/057201

We present a theoretical study of quantum charge pumping in metallic armchair graphene nanoribbons using the Floquet Green function method. A central part of the ribbon acting as the scattering region is supposed to have staggered sublattiee potential to open a finite band gap. A single ae gate is asymmetrically applied to a part of the scattering region to drive the pumping. Corresponding to the gap edges, there are two pumped current peaks with opposite current directions, which can be reversed by changing the position of the ac gate relative to the scattering region. The effects of the parameters, such as the staggered sublattice potential, the driving frequency and the geometric parameters of the structure, on the pumping are discussed.