Quantum effects in graphene monolayers: Path-integral simulations
arXiv:1612.07504 · doi:10.1063/1.4971453
Abstract
Path-integral molecular dynamics (PIMD) simulations have been carried out to study the influence of quantum dynamics of carbon atoms on the properties of a single graphene layer. Finite-temperature properties were analyzed in the range from 12 to 2000~K, by using the LCBOPII effective potential. To assess the magnitude of quantum effects in structural and thermodynamic properties of graphene, classical molecular dynamics simulations have been also performed. Particular emphasis has been laid on the atomic vibrations along the out-of-plane direction. Even though quantum effects are present in these vibrational modes, we show that at any finite temperature classical-like motion dominates over quantum delocalization, provided that the system size is large enough. Vibrational modes display an appreciable anharmonicity, as derived from a comparison between kinetic and potential energy of the carbon atoms. Nuclear quantum effects are found to be appreciable in the interatomic distance and layer area at finite temperatures. The thermal expansion coefficient resulting from PIMD simulations vanishes in the zero-temperature limit, in agreement with the third law of thermodynamics.
14 pages, 11 figures
References in corpus (17)
- The electronic properties of graphene
- The structure of suspended graphene sheets
- Thermal properties of graphene: Fundamentals and applications
- Electron scattering on microscopic corrugations in graphene
- Finite temperature lattice properties of graphene beyond the quasiharmonic approximation
- Nonlinear elasticity of monolayer graphene
- Midgap states and charge inhomogeneities in corrugated graphene
- Graphene as an electronic membrane
- Properties of discrete breathers in graphane from ab initio simulations
- State-of-the-art models for the phase diagram of carbon and diamond nucleation
- A path-integral molecular dynamics simulation of diamond
- Quasi-harmonic approximation of thermodynamic properties of ice Ih, II, and III
- Theory of anharmonic phonons in 2D crystals
- Anharmonic effects in the optical and acoustic bending modes of graphene
- Diffusion of muonium and hydrogen in diamond
- Hydrogen and muonium in diamond: A path-integral molecular dynamics simulation
- Density functional theory analysis of flexural modes, elastic constants, and corrugations in strained graphene