title: Charge-transfer-induced cesium superlattices on graphene.
abstract: We investigate cesium (Cs) adsorption on graphene formed on a 6H-SiC(0001) substrate by a combined scanning tunneling microscopy and density functional theory study. Individual Cs atoms adsorb preferentially at the rim region of the well-defined 6×6 substrate superstructure and on multilayer graphene. By finely controlling the graphene thickness and Cs coverages (1/3  ML and 1 ML), we here demonstrate two intriguing and well-ordered Cs superlattices on bilayer and multilayer graphene (<6   layers). Statistical analysis of the Cs-Cs interatomic distance reveals a hitherto unobserved Cs-Cs long-range electrostatic potential caused by charge transfer from Cs to graphene, which couples with the inhomogeneous substrate potential to stabilize the observed Cs superlattices. The present study provides a new avenue to fabricate atomic and molecular superlattices for applications in high-density recording and data storage.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Can-Li
authors.initials: CL
authors.lastname: Song
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.forename: Yi-Lin
authors.initials: YL
authors.lastname: Wang
authors.forename: Ye-Ping
authors.initials: YP
authors.lastname: Jiang
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Ke
authors.initials: K
authors.lastname: He
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Xu-Cun
authors.initials: XC
authors.lastname: Ma
authors.forename: Qi-Kun
authors.initials: QK
authors.lastname: Xue