Related papers: Improved data analysis for molecular dynamics in l…
We show that the slow viscoelastic response of a foam is that of a power-law fluid with a terminal relaxation. Investigations of the foam mechanics in creep and recovery tests reveal that the power-law contribution is fully reversible,…
We compute the dielectric response of glasses starting from a microscopic system-bath Hamiltonian of the Zwanzig-Caldeira-Leggett type and using an ansatz from kinetic theory for the memory function in the resulting Generalized Langevin…
The frequency dependent specific heat has been measured under pressure for the molecular glass forming liquid 5-polyphenyl-4-ether in the viscous regime close to the glass transition. The temperature and pressure dependence of the…
While the vibrational thermodynamics of materials with small anharmonicity at low temperatures has been understood well based on the harmonic phonons approximation; at high temperatures, this understanding must accommodate how phonons…
We present a theoretical derivation of acoustic phonon damping in amorphous solids based on the nonaffine response formalism for the viscoelasticity of amorphous solids. The analytical theory takes into account the nonaffine displacements…
We study a homogeneously driven granular fluid of hard spheres at intermediate volume fractions and focus on time-delayed correlation functions in the stationary state. Inelastic collisions are modeled by incomplete normal restitution,…
Equilibrium molecular dynamics simulations are performed to study two-dimensional (2D) dusty plasma liquids. Based on the stochastic thermal motion of simulated particles, the longitudinal and transverse phonon spectra are calculated, and…
Carbon tetrachloride (CCl$_4$) is one of the simplest compounds having a translationally stable monoclinic phase while exhibiting a rich rotational dynamics below 226 K. Recent nuclear quadrupolar resonance (NQR) experiments revealed that…
In the present study, quantitative feasibility tests of the hydrodynamic description of a two-dimensional fluid at the molecular level are performed, both with respect to length and time scales. Using high-resolution fluid velocity data…
Glassy polymers are central to engineering applications, yet their viscoelastic response over broad frequency and temperature ranges remains difficult to characterize. We extend non-affine deformation theory by incorporating a…
Phonon-derived behaviors are important indicators of novel phenomena in transition metal trihalides, including spin liquid behavior, two-dimensional magnetism, and spin-lattice coupling. However, phonons and their dependence on spin…
Transient reflectivity traces measured for nanometer-sized films of the topological insulator Bi2Se3 revealed GHz-range oscillations driven within the relaxation of hot carriers photoexcited with ultrashort laser pulses of 1.51 eV photon…
The high frequency dynamics of low- (LDA) and high-density amorphous-ice (HDA) and of cubic ice (I_c) has been measured by inelastic X-ray Scattering (IXS) in the 1-15 nm^{-1} momentum transfer (Q) range. Sharp phonon-like excitations are…
The speed of longitudinal sound waves at 7 and 22 MHz has been measured in liquid, supecooled, and amorphous selenium, including the region around the glass transition temperature, Tg, near 35 C. In amorphous selenium the speed of shear…
Terahertz time domain spectroscopy (THz TDS) is used to measure the melting kinetics of fructose molecular crystals. Combining single crystal anisotropy measurements with density functional calculations we assign the phonon frequencies and…
We present results of theoretical description of ultrasonic phenomena in molecular liquids. In particular, we are interested in the development of microscopical, i.e., statistical-mechanical framework capable to explain the long living…
We investigate the influence of dynamic heterogeneity on the spectral shape of structural relaxation in van der Waals liquids above the melting point by means of depolarized dynamic light scattering. To this end, we study optically…
We derive expressions for the intensity of the Brillouin polarized spectrum of a molecular liquid formed of axially symmetric molecules. These expressions take into account both the molecular dielectric anisotropy and the modulation of the…
Inelastic x-ray scattering (IXS) measurements of the dynamic structure factor in liquid Na57K43, sensitive to the atomic-scale coarse graining, reveal a sound velocity value exceeding the long wavelength, continuum value and indicate the…
The probing of coherent lattice vibrations in solids has been conventionally carried out using time-resolved transient spectroscopy where only the relative oscillation amplitude can be obtained. Using time-resolved X-ray techniques,…