Electronic and spin transport properties of zigzag graphene nanoribbon mediated by metal adatom: A study by QUAMBO-NEGF approach

TL;DR

This study investigates how cobalt adatoms affect the electronic and spin transport properties of zigzag graphene nanoribbons using a novel QUAMBO-NEGF approach, revealing spin-dependent transmission suppression below the Fermi level.

Contribution

It introduces a QUAMBO-NEGF method for analyzing electronic transport in large-scale systems and constructs accurate TB parameters for ZGNRs with adatoms.

Findings

Spin-dependent transmission suppression below Fermi level due to Co adatom

Slight distortion and spin independence above Fermi level

Successful reproduction of transmission behavior using divide-and-conquer approach

Abstract

Structural and electronic properties, including deformation, magnetic moment, Mulliken population, bond order as well as electronic transport properties, of zigzag graphene nanoribbon (ZGNR) with Co adatom on hollow site are investigated by quasi-atomic minimal basis orbits (QUAMBOs), a first-principles tight binding (TB) scheme based on density functional theory (DFT), combined with non-equilibrium Green's function. As for electronic transport, below Fermi level the transmission is strongly suppressed and spin-dependent as a result of magnetism by Co adatom adsorption, while above Fermi level the transmission is slightly distorted and spin-independent. Due to local environment dependence of QUAMBOs-TB parameters, we construct QUAMBOs-TB parameters of ZGNR lead and ZGNR with Co adatom on the hollow center site by divide-and-conquer approach, and well reproduce the electronic transmission behavior. Our QUAMBO-NEGF method is a new and promising way for electronic transport in large-scale system.