title: Understanding and tuning the quantum-confinement effect and edge magnetism in zigzag graphene nanoribbon.
abstract: The electronic structure of zigzag graphene nanoribbon (ZGNR) is studied using density functional theory. The mechanisms underlying the quantum-confinement effect and edge magnetism in ZGNR are systematically investigated by combining the simulated results and some useful analytic models. The quantum-confinement effect and the inter-edge superexchange interaction can be tuned by varying the ribbon width, and the spin polarization and direct exchange splitting of the edge states can be tuned by varying their electronic occupations. The two edges of ZGNR can be equally or unequally tuned by charge doping or Li adsorption, respectively. The Li adatom has a site-selective adsorption on ZGNR, and it is a nondestructive and memorable approach to effectively modify the edge states in ZGNR. These systematic understanding and effective tuning of ZGNR electronics presented in this work are helpful for further investigation and application of ZGNR and other magnetic graphene systems.
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, People's Republic of China.
authors.forename: Liang Feng
authors.initials: LF
authors.lastname: Huang
authors.forename: Guo Ren
authors.initials: GR
authors.lastname: Zhang
authors.forename: Xiao Hong
authors.initials: XH
authors.lastname: Zheng
authors.forename: Peng Lai
authors.initials: PL
authors.lastname: Gong
authors.forename: Teng Fei
authors.initials: TF
authors.lastname: Cao
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zeng