Related papers: TiC lattice dynamics from ab initio calculations
We use ultrafast optical spectroscopy to investigate the electronic and lattice dynamics of the charge-density wave (CDW) material 1$T$-TiSe$_2$ across various temperatures and pump fluences. We reveal a close relationship between the…
The stability of high-pressure phases of P has been studied using density functional theory and the local density approximation. Using a linear response technique, we have calculated the phonon spectrum and electron-phonon interaction for…
Phonon lifetime calculations from first principles usually rely on time consuming molecular dynamics calculations, or density functional perturbation theory (DFPT) where the zero temperature crystal structure is assumed to be dynamically…
We report an investigation of the lattice dynamical properties of LiFeAs using inelastic light scattering. Five out of the six expected phonon modes are observed. The temperature evolution of their frequencies and linewidths is in good…
The breakdown of Hooke's law marks the onset of nonlinear behaviour: when displacements become large, restoring forces weaken and conventional proportionality fails. In quantum materials, intense optical excitation can drive the crystal…
The competition between superconductivity and other ground states of solids is one of the challenging topics in condensed matter physics. Apart from high-temperature superconductors [1,2] this interplay also plays a central role in the…
An increasing number of theoretical calculations on few-layer materials have been reporting a non-zero sound velocity for all three acoustic phonon modes. In contrast with these reports, here we show that the lowest phonon dispersion branch…
A general procedure to investigate the elastic response and calculate the elastic constants of stressed and unstressed materials through continuum field modeling, particularly the phase field crystal (PFC) models, is presented. It is found…
Ultrathin FeSe films grown on SrTiO$_{3}$ substrates are a recent milestone in atomic material engineering due to their important role in understanding unconventional superconductivity in Fe-based materials. Using femtosecond time- and…
Taking into account the constraints imposed by the lattice symmetry, we calculate the phonon dispersion for graphene with interactions between the first, second, and third nearest neighbors in the framework of the Born--von Karman model.…
We describe a theoretical and computational approach to calculate the vibrational, elastic, and thermal properties of materials from the low-temperature quantum regime to the high-temperature anharmonic regime. This approach is based on…
Ferromagnetic \nmg has unique magnetoelastic properties. These are investigated by detailed computational studies of the phonon dispersion curves for the non-modulated cubic \Ltw and tetragonal structures. For the \Ltw\ structure, a…
Based on the formalism developed by Psarobas et al [Phys. Rev. B 62, 278(2000)], which using the multiple scattering theory to calculate properties of simple phononic crystals, we propose a very simple method to study the NaCl-type phononic…
In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions,…
Using first-principles calculations based on a variational density functional perturbation theory, we investigate the lattice dynamics of solid solutions of barium and strontium titanates. Averaging the information available for the related…
Cubic silicon carbide phonon thermal conductivity has been calculated using anharmonic phonon analysis. The atomic interaction model was built using displacement-force data obtained with the High Efficiency Configuration Space Sampling…
Phonon dispersions in <100> silicon nanowires (SiNW) are modeled using a Modified Valence Force Field (MVFF) method based on atomistic force constants. The model replicates the bulk Si phonon dispersion very well. In SiNWs, apart from four…
Diffusion is the underlying mechanism for many complicated materials phenomena, and understanding it is basic to the discovery of novel materials with desired physical and mechanical properties. Certain groups of solid phases, such as the…
We calculate the parameters describing elastic $I=1$, $P$-wave $\pi\pi$ scattering using lattice QCD with $2+1$ flavors of clover fermions. Our calculation is performed with a pion mass of $m_\pi \approx 320\:\:{\rm MeV}$ and a lattice size…
The pressure dependence of the Born effective charge, dielectric constant and zone-center LO and TO phonons have been determined for $3C$-SiC by a linear response method based on the linearized augmented plane wave calculations within the…