title: Probe of local impurity states by bend resistance measurements in graphene cross junctions.
abstract: We report on low-temperature transport measurements on four-terminal cross junction devices fabricated from high-quality graphene grown by chemical vapor deposition. At high magnetic fields, the bend resistance reveals pronounced peak structures at the quantum Hall plateau transition, which can be attributed to the edge state transport through the junctions. We further demonstrate that the bend resistance is drastically affected by the presence of local impurity states in the junction regions, and exhibits an unusual asymmetric behavior with respect to the magnetic field direction. The observations can be understood in a model taking into account the combination of the edge transport and an asymmetric scatterer. Our results demonstrate that a graphene cross junction may serve as a sensitive probe of local impurity states in graphene at the nanoscale.
authors.affiliation: Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Du
authors.forename: J Y
authors.initials: JY
authors.lastname: Li
authors.forename: N
authors.initials: N
authors.lastname: Kang
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.forename: Hailin
authors.initials: H
authors.lastname: Peng
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu
authors.forename: H Q
authors.initials: HQ
authors.lastname: Xu