Related papers: Phonon Kinetics at the Solid to Liquid Phase Trans…
Glasses are amorphous solids, in the sense that they display elastic behaviour. In crystals, elasticity is associated with phonons, quantized sound-wave excitations. Phonon-like excitations exist also in glasses at very high frequencies…
The all-temperature magnon (ATM) theory [J. Phys. Condens. Matter 21, 336003/1-14, 2009] has been used to analyze the temperature dependence of magnetization as well as the internal energy components of a mono-domain ferromagnetic solid.…
We show that electron drag by nonequilibrium phonons describes the actual waveform and spectrum of terahertz pulses generated during femtosecond laser irradiation of metals. In contrast to previous models, there is a picosecond delay in the…
Ultrafast two-dimensional spectroscopy utilizes correlated multiple light-matter interactions for retrieving dynamic features that may otherwise be hidden under the linear spectrum. Its extension to the terahertz regime of the…
Coherent sub-THz phonons incident on a gold grating that is deposited on a dielectric substrate undergo diffraction and thereby induce an alteration of the surface plasmon-polariton resonance. This results in efficient high-frequency…
We propose a biosensor based on the change of terahertz (THz) dielectric response when a biotarget binds to a probe. The feasibility of this biosensor is examined by studying the change of THz transmission for thin films of heme proteins…
Time-resolved diffuse scattering experiments have gained increasing attention due to their potential to reveal non-equilibrium dynamics of crystal lattice vibrations with full momentum resolution. Although progress has been made in…
We show clear experimental evidence of co-operative terahertz (THz) dynamics observed below 3 THz (~100 cm-1), for a low-symmetry Zr-based metal-organic framework (MOF) structure, termed MIL-140A [ZrO(O2C-C6H4-CO2)]. Utilizing a combination…
A direct band gap, remarkable light-matter coupling as well as strong spin-orbit and Coulomb interaction establish two-dimensional (2D) crystals of transition metal dichalcogenides (TMDs) as an emerging material class for fundamental…
Pump-probe reflectivity measurements have been performed on a single crystal of tungsten diselenide (WSe$_2$) using ultrashort near-infrared pulses. The behavior is well reproduced in simulations superimposing three oscillations (7.45, 7.49…
Hyperbolic phonon polariton is important in precisely controlling photons at the nanoscale. It was common practice to calculate the dielectric function of the phonon polariton system with the Drude-Lorenz model. We considered the impact of…
Brillouin spectroscopic measurements have been carried out on relaxor ferroelectric Pb(Zn1/3Nb2/3)0.85Ti0.15O3 (PZN-PT) single crystal over the temperature range 300-585 K. The longitudinal acoustic phonon begins to soften below 650 K,…
Coupling to phonon modes is a primary mechanism of excitonic dephasing and energy loss in semiconductors. However, low-energy phonons in colloidal quantum dots and their coupling to excitons are poorly understood, since their experimental…
We analyze ultrafast tunneling experiments in which electron transport through a localized orbital is induced by a single cycle THz pulse. We include both electron-electron and electron-phonon interactions on the localized orbital using the…
We report terahertz time-domain spectroscopy (TDTS) experiments demonstrating strong light-matter coupling in a terahertz (THz) LC-metamaterial in which the phonon resonance of a topological insulator (TI) thin film is coupled to the…
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…
Coupling between electrons and phonons (lattice vibrations) drives the formation of the electron pairs responsible for conventional superconductivity. The lack of direct evidence for electron-phonon coupling in the electron dynamics of the…
It is well established that nearly all high-quality (Q) Fano-like resonances in terahertz (THz) metasurfaces broaden as asymmetry increases, resulting in a decline of Q-factor and an increase in the resonance intensity. Therefore, in order…
The terahertz (THz) frequency range (0.1-10 THz) fills the gap between the microwave and optical parts of the electromagnetic spectrum. Recent progress in the generation and detection of the THz radiation has made it a powerful tool for…
We analyze the ground states and the elementary collective excitations (phonons) of a class of systems, which form cluster crystals in the absence of attractions. Whereas the regime of moderate-to-high-temperatures in the phase diagram has…