Related papers: Goldstone-Mode Phonon Dynamics in the Pyrochlore C…
Electronic Raman scattering and optical phonon self-energies are studied on single crystals of $LuB_{12}$ with different isotopic composition in the temperature region 10-650K and at pressures up to 10 GPa. The shape and energy position of…
Ba2YIrO6, a Mott insulator, with four valence electrons in Ir5+ d-shell (5d4) is supposed to be non-magnetic, with Jeff = 0, within the atomic physics picture. However, recent suggestions of non-zero magnetism have raised some fundamental…
We performed comparable polarized Raman scattering studies of MoTe2 and WTe2. By rotating crystals to tune the angle between the principal axis of the crystals and the polarization of the incident/scattered light, we obtained the angle…
Temperature dependent Raman scattering measurements have been performed to explore unusual coupling between magnetism and crystal structure in doped pyrochlore iridate Y$_2$(Ir$_{1-x}$Ru$_x$)$_2$O$_7$ with $x$ = 0.0, 0.05 and 0.2. The…
The Raman spectrum of the $B_{1g}$ phonon in the superconducting cuprate materials is investigated theoretically in detail in both the normal and superconducting phases, and is contrasted with that of the $A_{1g}$ phonon. A mechanism…
The electrical conductivity and Raman spectroscopy measurements have been performed on MoS$_2$ at high pressures up to 90 GPa and variable temperatures down to 5 K. We find that the temperature dependence of the resistance in a metallic…
In this paper, we present the spin-phonon coupling and dielectric response of nano-crystalline Pr$_2$CoMnO$_6$ employing Raman and dielectric spectroscopic study. Pr$_2$CoMnO$_6$ is a manganite compound , it undergoes a paramagnetic to…
We discuss the mechanism of coherent phonon generation by Stimulated Ionic Raman Scattering, a process different from conventional excitation with near visible optical pulses. Ionic Raman scattering is driven by anharmonic coupling between…
We report the first pyrochlore oxide superconductor Cd2Re2O7. Resistivity,magnetic susceptibility,and specific heat measurements on single crystals evidence a bulk superconductivity at 1 K. Another phase transition found at 200 K suggests…
The polarized Raman spectra of layered ruthenates of the Srn+1RunO3n+1 (n=1,2,3) Ruddlesden-Popper series were measured between 10 and 300 K. The phonon spectra of Sr3Ru2O7 and Sr4Ru3O10 confirmed earlier reports for correlated rotations of…
Sodium niobate (NaNbO3) exhibits most complex sequence of structural phase transitions in perovskite family and therefore provides as excellent model system for understanding the mechanism of structural phase transitions. We report…
Results of in-plane and out-of-plane thermal conductivity measurements on $\rm La_{1.8-x}Eu_{0.2}Sr_xCuO_4$ ($0\leq x\leq0.2$) single crystals are presented. The most characteristic features of the temperature dependence are a pronounced…
The 5d-transition metal pyrochlore oxide Cd2Re2O7, which was recently suggested to be a prototype of the spin-orbit-coupled metal [Phys. Rev. Lett. 115, 026401 (2015)], exhibits an inversion-symmetry breaking (ISB) transition at 200 K and a…
The emergence of scalar Higgs-type amplitude modes in systems where symmetry is spontaneously broken has been a highly successful, paradigmatic description of phase transitions, with implications ranging from high-energy particle physics to…
We report inelastic light scattering experiments on CaFe_2As_2 in the temperature range of 4 to 290 K. In in-plane polarizations two Raman-active phonon modes are observed at 189 and 211 cm-1, displaying A_1g and B_1g symmetries,…
In this work we study phonon-phonon coupling in bismuth vanadate (BiVO4), known for its second-order transition involving a variety of coupling mechanisms. Using Raman spectroscopy as a probe, we identify two optical coupled phonon modes of…
We study the valence crossover and strong electron-phonon coupling of EuPd$_2$Si$_2$ by polarization-resolved Raman spectroscopy. The fully-symmetric phonon mode shows strongly asymmetric lineshape at low temperature, indicating Fano-type…
Comprehensive inelastic neutron-scattering measurements were performed to study the soft optical phonons in La2-xSrxCuO4 at x=0.10, 0.12 and 0.18. We found at x=0.18 that the softening of Z-point phonon, suggesting incipient structural…
According to the Goldstone theorem the breaking of a continuous U(1) symmetry comes along with the existence of low-energy collective modes. In the context of superconductivity these excitations are related to the phase of the…
Critical behavior of the infrared reflectivity of RuSr_2GdCu_2O_8 ceramics is observed near the superconducting T_{SC} = 45 K and magnetic T_M = 133 K transition temperatures. The optical conductivity reveals the typical features of the…