Related papers: Temperature-dependent phonon spectra of magnetic r…
A comprehensive picture of polaron and bipolaron physics is essential to understand the optical absorption spectrum in many materials with electron-phonon interactions. In particular, the finite-temperature properties are of interest since…
Understanding the microscopic processes affecting the bulk thermal conductivity is crucial to develop more efficient thermoelectric materials. PbTe is currently one of the leading thermoelectric materials, largely thanks to its low thermal…
We study theoretically the fluctuation properties of acoustic phonons created in a semiconductor quantum dot after ultrafast optical excitation. An excitation with a single ultrafast pulse creates an exciton confined to the quantum dot,…
All phonons in a single crystal of NaBr were measured by inelastic neutron scattering at temperatures of 10, 300 and 700 K. Even at 300 K the phonons, especially the longitudinal-optical (LO) phonons, showed large shifts in frequencies, and…
We present a robust reciprocal-space implementation of the temperature-dependent effective potential method. Our implementation can scale easily to large cell and long sampling time. It is interoperable with standard ab-initio molecular…
The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time…
Acoustic phonons have recently been posited as playing an integral role in explaining the half-quantized thermal Hall effect in $\alpha$-RuCl$_3$. Therefore, we present much needed inelastic x-ray scattering measurements of its acoustic…
Although extensive experimental and theoretical works have been conducted to understand the ballistic and diffusive phonon transport in nanomaterials recently, direct observation of temperature and thermal nonequilibrium of different phonon…
Owing to their long phonon mean free paths (MFPs) and high thermal conductivity, carbon nanotubes (CNTs) are ideal candidates for, e.g., removing heat from electronic devices. It is unknown, however, how the intrinsic phonon MFPs depend on…
We conduct first-principles theoretical studies to investigate the temperature-dependent phonon properties of orthorhombic SrZrO$_3$ (SZO) perovskite. Our calculations include the quasiharmonic approximation, in which we explored mode…
We calculate the temperature dependence of NMR relaxation rate and electrical resistivity for coupling to a local, strongly anharmonic phonon mode. We argue that the two-phonon Raman process is dominating NMR relaxation. Due to the strong…
Metal-organic frameworks often display large positive or negative thermal expansion coefficients. MOF-74, a material envisioned for many applications does not display such a behavior. For this system, temperature-dependent x-ray diffraction…
We have investigated the dynamical properties of coherent phonons generated in antimony under high density photo excitation. Precise measurements and extended analysis of coherent phonon oscillations provide new insights into the process of…
A simple bulk model of electron-phonon coupling in metals has been surprisingly successful in explaining experiments on metal films that actually involve surface- or other low-dimensional phonons. However, by an exact application of this…
The origins of the anomalous temperature dependence of magnetocrystalline anisotropy in (Fe$_{1-x}$Co$_{x}$)$_{2}$B alloys are elucidated using first-principles calculations within the disordered local moment model. Excellent agreement with…
First principles-based predictions of lattice thermal conductivity (TC) from perturbation theory have achieved significant success. Usually, it only included three-phonon (3ph) scattering processes, only recently four-phonon (4ph)…
A new thermodynamic state function is introduced to describe the thermodynamics relevant for the mean transverse momentum fluctuations of charged particles in heavy-ion collisions, which allows us to compute the temperature fluctuations of…
The thermal expansion behavior of metal fluorides can be tuned by choosing appropriate metal cation. We present ab-initio lattice dynamical studies on the metal fluorides (CaZrF6, MgZrF6 and SrZrF6) and identify the anharmonic phonon modes…
Infrared reflection and transmission as a function of temperature have been measured on single crystals of Cu$_{3}$Bi(SeO$_{3}$)$_{2}$O$_{2}$Cl. The complex dielectric function and optical properties along all three principal axes of the…
We investigate the dispersion and temperature dependence of a number of phonons in the recently discovered superconductor CaC6 utilizing inelastic x-ray scattering. Four [00L] and two ab-plane phonon modes are observed, and measured at…