title: Uniaxial Strain Redistribution in Corrugated Graphene: Clamping, Sliding, Friction, and 2D Band Splitting.
abstract: Graphene is a promising material for strain engineering based on its excellent flexibility and elastic properties, coupled with very high electrical mobility. In order to implement strain devices, it is important to understand and control the clamping of graphene to its support. Here, we investigate the limits of the strong van der Waals interaction on friction clamping. We find that the friction of graphene on a SiO2 substrate can support a maximum local strain gradient and that higher strain gradients result in sliding and strain redistribution. Furthermore, the friction decreases with increasing strain. The system used is graphene placed over a nanoscale SiO2 grating, causing strain and local strain variations. We use a combination of atomic force microscopy and Raman scattering to determine the friction coefficient, after accounting for compression and accidental charge doping, and model the local strain variation within the laser spot size. By using uniaxial strain aligned to a high crystal symmetry direction, we also determine the 2D Raman Grüneisen parameter and deformation potential in the zigzag direction.
authors.affiliation: Department of Electrical and Computer Engineering, Boston University , 8 St. Mary's Street, Boston, Massachusetts 02215, United States.
authors.forename: Xuanye
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, Boston University , 8 St. Mary's Street, Boston, Massachusetts 02215, United States.
authors.forename: Khwanchai
authors.initials: K
authors.lastname: Tantiwanichapan
authors.affiliation: Department of Physics, Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States.
authors.forename: Jason W
authors.initials: JW
authors.lastname: Christopher
authors.affiliation: Department of Electrical and Computer Engineering, Boston University , 8 St. Mary's Street, Boston, Massachusetts 02215, United States.|Photonics Center, Boston University , 8 St. Mary's Street, Boston, Massachusetts 02215, United States.
authors.forename: Roberto
authors.initials: R
authors.lastname: Paiella
authors.affiliation: Department of Electrical and Computer Engineering, Boston University , 8 St. Mary's Street, Boston, Massachusetts 02215, United States.|Department of Physics, Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States.|Photonics Center, Boston University , 8 St. Mary's Street, Boston, Massachusetts 02215, United States.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Swan
keywords: 2D mode Grüneisen parameter; Raman spectroscopy; corrugated surface; friction; graphene; strain engineering