Related papers: Bending modes, anharmonic effects and thermal expa…
We study the electronic properties of commensurate faulted bilayer graphene by diagonalizing the one-particle Hamiltonian of the bilayer system in a complete basis of Bloch states of the individual graphene layers. Our novel approach is…
We present a mainly analytical study of the entanglement spectrum of Bernal-stacked graphene bilayers in the presence of trigonal warping in the energy spectrum. Upon tracing out one layer, the entanglement spectrum shows qualitative…
We study thermal fluctuations of a free-standing bilayer graphene subject to vanishing external tension. Within a phenomenological theory, the system is described as a stack of two continuum crystalline membranes, characterized by finite…
Graphene bilayers display peculiar electronic and mechanical characteristics associated to their two-dimensional character and relative disposition of the sheets. Here we study nuclear quantum effects in graphene bilayers by using…
We have investigated the effects of inplane and interplane nearest neighbour overlap integrals ($s_0$ and $s_1$) and site energy difference between atoms in two different sublattices in the same graphene layer ($\Delta$) on the electronic…
Based on the first principles calculation combined with quasi-harmonic approximation, in this work we focus on the analysis of temperature dependent lattice geometries, thermal expansion coefficients, elastic constants and ultimate strength…
The thermal expansion coefficient (TEC) of single-layer graphene is estimated with temperature-dependent Raman spectroscopy in the temperature range between 200 and 400 K. It is found to be strongly dependent on temperature but remains…
The influence of nanostructuring and quantum confinement on the thermoelectric properties of materials has been extensively studied. While this has made possible multiple breakthroughs in the achievable figure of merit, classical…
A unified approach is used to study vibrational properties of periodic systems with first-principles methods and including anharmonic effects. Our approach provides a theoretical basis for the determination of phonon-dependent quantities at…
Using a realistic model, the mode Gruneisen parameters and the temperature dependent coefficient of linear thermal expansion are calculated for amorphous silicon. The resulting values of the Gruneisen parameters differ from the crystalline…
We study conductance across a twisted bilayer graphene coupled to single-layer graphene leads in two setups: a flake of graphene on top of an infinite graphene ribbon and two overlapping semi-infinite graphene ribbons. We find conductance…
A definition of the Gr\"uneisen parameters for anisotropic materials is derived based on the response of phonon frequencies to uniaxial stress perturbations. This Gr\"uneisen model relates the thermal expansion in a given direction…
We investigate the in-plane oscillations of the relaxed shape graphene due to externally applied tensile edge stress along both the armchair and zigzag directions. We show that the total elastic energy density is enhanced with temperature…
The intrinsic channel properties of monolayer and multilayer graphene were systematically investigated as a function of layer number by the exclusion of contact resistance using four-probe measurements. We show that the continuous change in…
Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with…
Theoretical investigation of thermodynamic properties of electrically modulated monolayer graphene in the presence of a perpendicular magnetic field B is presented.This work is aimed at determining the modulation induced effects on the…
The freestanding twisted bilayer graphene (TBG) is unstable, below a critical twist angle {\theta}_c~3.7 degrees, against a moire (2 \times 1) buckling distortion at T=0. Realistic simulations reveal the concurrent unexpected collapse of…
Graphene and few-layer graphene at high bias expose a wealth of phenomena due to the high temperatures reached. With in-situ transmission electron microscopy (TEM) we observe directly how the current modifies the structure, and vice versa.…
We study the variations of electron-phonon coupling and their spectroscopic consequences in response to sliding of two layers in bilayer graphene using first-principles calculations and a model Hamiltonian. Our study shows that the long…
Despite many of the applications of graphene rely on its uneven stiffness and high thermal conductivity, the mechanical properties of graphene, and in general of all 2D materials, are still elusive. The harmonic theory predicts a quadratic…