相关论文: Phonon-phonon interactions in transition metals

We report a Raman study of the effect of temperature on the self-energies of optical phonons in a number of transition metals with hexagonal-close-packed structure. Anisotropic softening of phonon energies and narrowing of phonon linewidths…

Time-resolved Raman spectroscopy has been applied to probe the anharmonic coupling and electron-phonon interaction of optical phonons in graphite. From the decay of the transient anti-Stokes scattering of the G-mode following ultrafast…

A nonperturbative theory of multiphonon anharmonic transitions between energy levels of a local mode is presented. It is shown that the rate of transitions rearranges near the critical level number $n_{cr}$: at smaller $n$ the process slows…

The anharmonic contribution to phonon lifetime and its temperature dependence is calculated from first principle in C, Si and Ge using third-order density-functional perturbation theory. Good agreement with available experimental data is…

We use a hybrid strategy to obtain anharmonic frequency shifts and lifetimes of phonon quasi-particles from first principles molecular dynamics simulations in modest size supercells. This approach is effective irrespective of crystal…

Explicit expressions for anharmonic contributions to the thermodynamic properties with allowance for higher-order phonon-phonon interactions for closed-packed crystals are given, and the calculations for some fcc metals near the melting…

Phonon quasi-particles have been monumental in microscopically understanding thermodynamics and transport properties in condensed matter for decades. Phonons have one-to-one correspondence with harmonic eigenstates and their energies are…

We have calculated (ab initio) and measured (by spin-echo techniques) the anharmonic self-energy of phonons at the X-point of the Brillouin zone for isotopically pure germanium. The real part agrees with former, less accurate, high…

The dispersion in the entire Brillouin zone and the temperature dependence (right up to the melting temperature) of the anharmonic frequency shift and phonon damping in a number of fcc metals is investigated on the basis of microscopic…

Using an atomistic model that simultaneously treats the dynamics of translational and spin degrees of freedom, we perform combined molecular and spin dynamics simulations to investigate the mutual influence of the phonons and magnons on…

Lattice vibrations in CH$_3$NH$_3$PbI$_3$ are strongly interacting, with double well instabilities present at the Brillouin zone boundary. Analysis within a first-principles lattice dynamics framework reveals anharmonic potentials with…

Phonon densities of states (DOS) of bcc $\alpha$-$^{57}$Fe were measured from room temperature through the 1044K Curie transition and the 1185K fcc $\gamma$-Fe phase transition using nuclear resonant inelastic x-ray scattering. At higher…

We present Raman measurements on the iron-pnictide superconductors CeFeAsO_{1-x}F_{x} and NdFeAsO{1-x}F_{x}. Modeling the Fe-As plane in terms of harmonic and a cubic anharmonic Fe-As interaction we calculate the temperature dependence of…

Natural materials usually consist of isotopic mixtures, for which different isotopic ratios can lead to distinct material properties such as thermal conductivity and nucleation process. However, the knowledge of isotopic interface remains…

We determine from first-principles the finite-temperature properties--linewidths, line shifts, and lifetimes--of the key vibrational modes that dominate inelastic losses in graphitic materials. In graphite, the phonon linewidth of the…

We investigate phonon lifetimes in VO2 single crystals. We do so in the metallic state above the metal-insulator transition (MIT), where strong structural fluctuations are known to take place. By combining inelastic X-ray scattering and…

We observe anharmonic decay of the photoexcited coherent A1g phonon in bismuth to points in the Brillouin zone where conservation of momentum and energy are satisfied for three-phonon scattering. The decay of a coherent phonon can be…

In this work, we have studied the phonon properties of multi-layered graphene with the use of Molecular Dynamics (MD) simulations and the k-space Autocorrelation Sequence (k-VACS) method. We calculate the phonon dispersion curves, densities…

Lattice thermal conductivities of zincblende- and wurtzite-type compounds with 33 combinations of elements are calculated with the single-mode relaxation-time approximation and linearized phonon Boltzmann equation from first-principles…

We present a calculation of the Hg phonon self-energy for a model of A3C60 (A= K, Rb). The orientational disorder of the C60 molecules is included, and the lowest order self-energy diagram is considered. The calculations illustrate that due…