Related papers: Fluctuation-enhanced electron-phonon coupling in F…
The elastic collective modes of a moir\'e superlattice arise not from vibrations of a rigid crystal but from the relative displacement between the constituent layers. Despite their similarity to acoustic phonons, these modes, called…
The lattice dynamics of FeSb2 is investigated by the first-principles DFT calculations and Raman spectroscopy. All Raman and infra-red active phonon modes are properly assigned. The calculated and measured phonon energies are in good…
The phonon dispersion was measured at room temperature along (0,0,L) in the tetragonal phase of LaFeAsO using inelastic x-ray scattering. Spin-polarized first-principles calculations imposing various types of antiferromagnetic order are in…
We report measurements of the temperature dependence of phonon densities of states in K0.8Fe1.6Se2 using inelastic neutron scattering technique. While cooling down to 150 K, a phonon peak splitting around 25 meV is observed and a new peak…
An investigation of possibilities for superconductivity mediated by spin fluctuations in some elementary metals is motivated by the recent discovery of superconductivity in the hcp high-pressure phase of iron. The electronic structure, the…
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,…
We used polarization-resolved Raman scattering to study the magneto-elastic coupling in the parent compounds of several families of Fe-based superconductors (BaFe2As2, EuFe2As2, NaFeAs, LiFeAs, FeSe and LaFeAsO). We observe an emergent…
We report inelastic light scattering experiments on superconductor Ce0.6Y0.4FeAsO0.8F0.2 from 4K to 300K covering the superconducting transition temperature Tc ~ 48.6K. A strong evidence of the superconductivity induced phonon…
We investigated microscopic lattice states in the donor-acceptor ionic Mott insulator, TTF-BA, by $^{79}$Br-NQR spectroscopy to explore cross-correlated fluctuations between spin, charge and lattice. A ferroelectric transition with lattice…
To gain control over magnetic order on ultrafast time scales, a fundamental understanding of the way electron spins interact with the surrounding crystal lattice is required. However, measurement and analysis even of basic collective…
We present a systematic study of the structure and lattice dynamics at room temperature, and the phonon behavior at low temperatures in orthorhombic Gd$_{1-x}$Y$_{x}$MnO$_{3}$ manganites, with 0 $\leq$ x $\leq$ 0.4, using powder x-ray…
We present a comprehensive investigation of lattice dynamics in the double-helix antiferromagnet FeP by means of high-resolution time-of-flight neutron spectroscopy and ab-initio calculations. Phonons can hybridize with the magnetic…
We employed femtosecond time- and angle-resolved photoelectron spectroscopy to analyze the response of the electronic structure of the 122 Fe-pnictide parent compounds Ba/EuFe_2As_2 and optimally doped BaFe_{1.85}Co_{0.15}As_2 near the…
We report measurements of the phonon density of states as measured with inelastic x-ray scattering in SmFeAsO$_{1-x}$F$_y$ powders. An unexpected strong renormalization of phonon branches around 23 meV is observed as fluorine is substituted…
Fe$_{1.057(7)}$Te undergoes a first-order tetragonal to monoclinc structural transition at T$_{S} \sim 70$ K, breaking the C$_{4}$ lattice symmetry and simultaneously breaking time reversal symmetry with bicollinear magnetic order. We…
Quasiparticle dynamics of FeSe single crystals revealed by dual-color transient reflectivity measurements ({\Delta}R/R) provides unprecedented information on Fe-based superconductors. The amplitude of fast component in {\Delta}R/R clearly…
We have performed powder inelastic neutron scattering measurements on the unconventional superconductor $\beta$-FeSe ($T_{\rm c} \simeq 8\,\mathrm{K}$). The spectra reveal highly dispersive paramagnetic fluctuations emerging from the…
In single unit-cell FeSe grown on SrTiO3, the superconductivity transition temperature features a significant enhancement. Local phonon modes at the interface associated with electron-phonon coupling may play an important role in the…
In Eu2ZnIrO6, effectively two atoms are active i.e. Ir is magnetically active, which results in complex magnetic ordering within the Ir sublattice at low temperature. On the other hand, although Eu is a van-vleck paramagnet, it is active in…
Symmetry breaking across phase transitions often causes changes in selection rules and emergence of optical modes which can be detected via spectroscopic techniques or generated coherently in pump-probe experiments. In second-order or…