1301.4936 (P. L. de Andres et al.)

Density functional theory analysis of flexural modes, elastic constants,
and corrugations in strained graphene    [PDF]

P. L. de Andres, F. Guinea, M. I. Katsnelson

Ab initio density functional theory has been used to analyze flexural modes, elastic constants, and atomic corrugations on single and bi-layer graphene. Frequencies of flexural modes are sensitive to compressive stress; its variation under stress can be related to the anomalous thermal expansion via a simple model based in classical Elasticity Theory [Phys. Rev. B 86, 144103]. Under compression, flexural modes are responsible for a long wavelength rippling with a large amplitude and a marked anharmonic behavior. This is compared with corrugations created by thermal fluctuations and the adsorption of a light impurity (hydrogen). Typical values for the later are in the sub-Angstrom regime, while maximum corrugations associated to bending modes quickly increase up to a few Angstroms under a compressive stress, due to the intrinsic instability of flexural modes

View original: http://arxiv.org/abs/1301.4936