Efficient charge pump by pure mechanical resonators in graphene

¹ Department of Physics, Southeast University - Nanjing, 210096, PRC
² Department of Physics, South University of Science and Technology of China - Shenzhen 518055, PRC

^(a) jwang@seu.edu.cn
^(b) liujf@sustc.edu.cn

Received: 20 October 2017
Accepted: 4 April 2018

Abstract

Graphene is an ideal two-dimensional nanoelectromechanical material due to its outstanding elastic properties and superior electro-mechanical coupling. We study a graphene-based charge pump by two mechanical resonators out of phase. It is found that in the adiabatic limit, the pumped charge per mode is quantized in a pumping cycle and the electro-mechanical conversion efficiency is maximally saturated, as long as the mechanical lattice deformations produce a transport gap for massless Dirac electrons. The efficient charge pump originates from the definite chirality of Dirac electrons as well as the possible topological interface state forming in the evanescent modes. Our findings might shed light on enhancing the electro-mechanical conversion efficiency of graphene-based devices.