Related papers: Atomic-charge distribution in glasses by terahertz…
The distribution of Ge-O-Ge and Si-O-Si bond angles alpha in amorphous germania and silica is re-determined on the basis of diffraction experiments. The bond angle alpha joining adjacent tetrahedra is the central parameter of any continuous…
The structure of (GeS$_2$)$_{0.75}$(Ga$_2$S$_3$)$_{0.25}$ and (GeS$_2$)$_{0.83}$(Ga$_2$S$_3$)$_{0.17}$ glasses was investigated by Raman scattering, high energy X-ray diffraction and extended X-ray absorption fine structure (EXAFS)…
With the use of {\em ab initio} based molecular dynamics simulations we study the structural, dynamical and electronic properties of glassy g-GeS$_2$ at room temperature. From the radial distribution function we find nearest neighbor…
The model glass-former glycerol and its aqueous mixtures were investigated with terahertz-time domain spectroscopy (THz-TDS) in the frequency range of 0.3--3.0\,THz at temperatures from 80--305\,K. It was shown that the infrared absorption…
A theory of weakly-nonlinear low-temperature relaxational absorption of acoustic and electromagnetic waves in dielectric and metallic glasses is developed. Basing upon the model of two-level tunneling systems we show that the nonlinear…
In order to understand whether internal stresses in glasses are correlated or randomly distributed, we study the organization of atomic bond tensions (normal forces between pairs of atoms). Measurements of the invariants of the atomic bond…
We study graphene on a photonic crystal operating in the terahertz (THz) spectral range. We show that the absorption of graphene becomes a modulated function of frequency and can be enhanced by more than three times at specific frequency…
Using an analytical theory, experimental terahertz time-domain spectroscopy data and numerical evidence, we demonstrate that the frequency dependence of the absorption coupling coefficient between far-infrared photons and atomic vibrations…
We compare the observed strong saturation of the free carrier absorption in n-type semiconductors at 300 K in the terahertz frequency range when single-cycle pulses with intensities up to 150 MW/cm2 are used. In the case of germanium, a…
A dynamical theory is constructed to describe spectral diffusion in glasses in the temperature range near 1 Kelvin on long time scales. The theory invokes interacting tunneling centers (TLS) which provide an excess contribution to the…
We report an integrated all-optical radio frequency spectrum analyzer based on a ~ 4cm long doped silica glass waveguide, with a bandwidth greater than 2.5 THz. We use this device to characterize the intensity power spectrum of ultrahigh…
Collinear phase-matched optical rectification is studied in ZnGeP$_{2}$ pumped with near-infrared light. The pump-intensity dependence is presented for three crystal lengths (0.3, 1.0 and 3.0 mm) to determine the effects of linear optical…
The upcoming flexible ultra-thin glass for foldable displays has attracted widespread attention as an alternative to rigid electronic smartphones. However, the detailed compositional effect of the chemical strengthening of the glass is not…
Experimentally resolving atomic-scale structural changes of a deformed glass remains challenging owing to the disordered nature of glass structure. Here, we show that the structural anisotropy emerges as a general hallmark for different…
X-ray photon correlation is used to probe the slow dynamics of the glass-former B2O3 across the glass transition. In the undercooled liquid phase the decay times of the measured correlation functions are consistent with visible light…
We present density-functional theory calculations of the optical absorption spectra of silica glass for temperatures up to 2400 K. The calculated spectra exhibit exponential tails near the fundamental absorption edge that follow the Urbach…
Probing vibronic coherence in molecules has been a central topic in ultrafast science, as it is an essential prerequisite to monitoring electronic motion. While experiments have demonstrated that attosecond transient absorption spectroscopy…
We present experimental results on the optical absorption spectra of epitaxial graphene from the visible to the terahertz (THz) frequency range. In the THz range, the absorption is dominated by intraband processes with a frequency…
The terahertz spectra of the dynamic conductivity and radiation absorption coefficient in germanium-silicon heterostructures with arrays of Ge hut clusters (quantum dots) have been measured for the first time in the frequency range of…
The dynamics of glass formation in monatomic and binary liquids are studied numerically using a microscopic field theory for the evolution of the time-averaged atomic number density. A stochastic framework combining phase field crystal free…