title: Manipulation and characterization of aperiodical graphene structures created in a two-dimensional electron gas.
abstract: We demonstrate that Dirac fermions can be created and manipulated in a two-dimensional electron gas (2DEG). Using a cryogenic scanning tunneling microscope, we arranged coronene molecules one by one on a Cu(111) surface to construct artificial graphene nanoribbons with perfect zigzag (ZGNRs) or arm-chairedges and confirmed that new states localized along the edges emerge only in the ZGNRs. We further made and studied several typical defects, such as single vacancies, Stone-Wales defects, and dislocation lines, and found that all these defects introduce localized states at or near the Dirac point in the quasiparticle spectra. Our results confirm that artificial systems built on a 2DEG provide rigorous experimental verifications for several long-sought theoretical predications of aperiodic graphene structures.
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Shiyong
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720-7300, USA and Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Liang Z
authors.initials: LZ
authors.lastname: Tan
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720-7300, USA and Material Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA and Institute for Advanced Study, Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Louie
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Nian
authors.initials: N
authors.lastname: Lin