Related papers: Phonon anharmonic frequency shift induced by four-…
Stimulated Brillouin scattering (SBS), an optical nonlinearity arising from photon-phonon interactions, has formed the basis for a large class of optical signal processing devices, including Brillouin amplifiers. A limiting factor of such…
We calculate the $T$-matrices of elastic pion-nucleon ($\pi N$) scattering up to fourth order in SU(3) heavy baryon chiral perturbation theory. The pertinent low-energy constants are determined by fitting to $\pi N$ phase shifts below 200…
It is shown that the nearest neighbor coupling between the carbon atoms is not enough to reproduce the phonon spectrum as observed in graphene, the second neighbor force constant is essential. For completeness we have rederived the phonon…
Density functional perturbation theory calculations of alpha-quartz using extended norm conserving pseudopotentials have been used to study the elastic properties and phonon dispersion relations along various high symmetry directions as a…
The discrete energy-eigenvalues of two nucleons interacting with a finite-range nuclear force and confined to a harmonic potential are used to numerically reconstruct the free-space scattering phase shifts. The extracted phase shifts are…
The class of layered 3D-topological insulators have shown intriguingly anomalous temperature dependence in their thermal expansion coefficients. It was proposed that stacking faults are the origin of the observed anomalous thermal…
Phonon transport across a vacuum gap separating intrinsic silicon crystals is predicted via the atomistic Green's function method combined with first-principles calculations of all interatomic force constants. The overlap of electron wave…
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…
Phonon, the collective excitation of lattice vibration in the crystal, has been put forward as a means to search for light dark matter. However, the accurate modeling of the multi-phonon production process is challenging in theory. The…
We explore a novel coupling mechanism of electrons with the transverse optical (TO) phonon branch in a regime when the TO mode becomes highly anharmonic and drives the ferroelectric phase transition. We show that this anharmonicity, which…
Understanding and predicting lattice dynamics in strongly anharmonic crystals is one of the long-standing challenges in condensed matter physics. Here we propose a first-principles method that gives accurate quasiparticle (QP) peaks of the…
We develop an ab initio framework that captures the impact of electron-electron and electron-hole interactions on phonon properties. This enables the inclusion of excitonic effects in the optical phonon dispersions and lifetimes of…
Phonon-mediated thermal conductivity, which is of great technological relevance, fundamentally arises due to anharmonic scattering from interatomic potentials. Despite its prevalence, accurate first-principles calculations of thermal…
Acoustic phonons play a special role in lattice heat transport, and confining these low-energy modes in low-dimensional materials may enable nontrivial transport phenomena. By applying lowest-order anharmonic perturbation theory to an…
Possible variations in the dynamical behaviour of LiYF$_{4}$ due to its several structural changes under pressure are examined by making use of the complementary techniques of quasi-harmonic lattice dynamics and molecular dynamics…
The microscopic origin of the large negative thermal expansion of cubic scandium trifluorides (ScF3) is investigated by performing a set of anharmonic free-energy calculations based on density functional theory. We demonstrate that the…
Effects of strong phonon anharmonicity of a type-I clathrate Ba$_{\rm 8}$Ga$_{\rm 16}$Sn$_{\rm 30}$ induced by quadruple-well potential of guest atoms were investigated. Phonon transport including coherent interbranch component was analyzed…
We propose a theory to explain the strain dependence of the critical properties in A15 superconductors. Starting from the strong-coupling formula for the critical temperature, and assuming that the strain sensitivity stems mostly from the…
Single-crystal diffuse scattering data have been collected at room temperature on synthetic titanite using both neutrons and high-energy X-rays. A simple ball-and-springs model reproduces the observed diffuse scattering well, confirming its…
This is the third article in a series of three papers on the resonance energy levels of anharmonic oscillators. Whereas the first two papers mainly dealt with double-well potentials and modifications thereof [see J. Zinn-Justin and U. D.…