Title: Electron-Hole Symmetry Breaking in Charge Transport in Nitrogen-Doped Graphene,
Abstract: Graphitic nitrogen-doped graphene is an excellent platform to study
scattering processes of massless Dirac fermions by charged impurities, in which
high mobility can be preserved due to the absence of lattice defects through
direct substitution of carbon atoms in the graphene lattice by nitrogen atoms.
In this work, we report on electrical and magnetotransport measurements of
high-quality graphitic nitrogen-doped graphene. We show that the substitutional
nitrogen dopants in graphene introduce atomically sharp scatters for electrons
but long-range Coulomb scatters for holes and, thus, graphitic nitrogen-doped
graphene exhibits clear electron-hole asymmetry in transport properties.
Dominant scattering processes of charge carriers in graphitic nitrogen-doped
graphene are analyzed. It is shown that the electron-hole asymmetry originates
from a distinct difference in intervalley scattering of electrons and holes. We
have also carried out the magnetotransport measurements of graphitic
nitrogen-doped graphene at different temperatures and the temperature
dependences of intervalley scattering, intravalley scattering and phase
coherent scattering rates are extracted and discussed. Our results provide an
evidence for the electron-hole asymmetry in the intervalley scattering induced
by substitutional nitrogen dopants in graphene and shine a light on versatile
and potential applications of graphitic nitrogen-doped graphene in electronic
and valleytronic devices.