Related papers: Electron-Phonon Coupling and the Soft Phonon Mode …
Very recently a new family of layered materials, containing BiS2 planes was discovered to be superconducting at temperatures up to Tc=10 K, raising questions about the mechanism of superconductivity in these systems. Here, we present…
We present a density functional perturbation theory approach to estimate the transition temperature of the charge density wave transition of TiSe2. The softening of the phonon mode at the L-point where in TiSe2 a giant Kohn anomaly occurs,…
Femtosecond core-level transient absorption spectroscopy is utilized to investigate photoinduced dynamics of the charge density wave in 1T-TiSe2 at the Ti M2,3 edge (30-50 eV). Photoexcited carriers and phonons are found to primarily induce…
I study the lattice dynamics and electron-phonon coupling in non-centrosymmetric quasi-one-dimensional K$_2$Cr$_3$As$_3$ using density functional theory based first principles calculations. The phonon dispersions show stable phonons without…
Using time- and angle-resolved photoemission spectroscopy with selective near- and mid-infrared photon excitations, we investigate the femtosecond dynamics of the charge density wave (CDW) phase in 1$T$-TiSe$_2$, as well as the dynamics of…
Layered 1$T$-TiSe$_{2}$ has attracted much interest for the competition of charge density wave (CDW) and superconductivity in its bulk and even monolayer forms. Here we perform first-principles calculations of the electronic structure,…
In this work we present the results of an inelastic x-ray scattering experiment detailing the behavior of the transverse acoustic [110] phonon in BaFe2As2 as a function of temperature. When cooling through the structural transition…
It is shown on the basis of the multiplicative renormalization-group method of two-loop order that the low-energy effective Hamiltonian of a strongly coupled local electron-phonon system is mapped to the two-channel Kondo model. A phonon is…
Superconductivity emerges in $1T$-TiSe$_2$ when its charge density wave (CDW) order is suppressed by Cu intercalation or pressure. Since the CDW state is thought to be an excitonic insulator, an interesting question is whether the…
The optical reflectivity of Pb$_{0.865}$Sn$_{0.135}$Se and Pb$_{0.75}$Sn$_{0.25}$Se solid solutions was measured in the THz spectral region energetically corresponding to bulk optical phonon excitations and in the temperature range from 40…
We report on the dynamics of coherent phonons in semimetal 1T'-MoTe2 using femtosecond pump-probe spectroscopy. On an ultrafast sub-picosecond time scale at room temperature, a low frequency and long-lifetime shear phonon mode was observed…
Understanding of electron-phonon coupling (EPC) in two dimensional (2D) materials manifesting as phonon renormalization is essential to their possible applications in nanoelectronics. Here we report in-situ Raman measurements of…
The temperature and pressure dependence of the partial density of phonon states of iron atoms in superconducting Fe1.01Se was studied by 57Fe nuclear inelastic scattering (NIS). The high energy resolution allows for a detailed observation…
We present electronic structure calculations, electrical resistivity data and the first specific heat measurements in the normal and superconducting states of quasi-one-dimensional M2Mo6Se6 (M = Tl, In, Rb). Rb2Mo6Se6 undergoes a…
We predict a possible phonon softening instability in strongly correlated coupled semiconductor bilayer systems. By studying the plasmon-phonon coupling in coupled bilayer structures, we find that the renormalized acoustic phonon frequency…
The interplay between electronic and lattice degrees of freedom is fundamental to charge density wave (CDW) formation, yet the microscopic origin often remains elusive. Here, we investigate the transient optical response of the…
Superconductivity in novel bismuth-sulphur superconductors has attracted large research efforts, both experimental and theoretical, but a consensus on the nature of superconductivity in these materials has yet to be reached. Using density…
We show that the electron-phonon coupling in graphene, in contrast with the non-relativistic two-dimensional electron gas, leads to shifts in the phonon frequencies that are non-trivial functions of the electronic density. These shifts can…
This paper reports the first experimental observation of phonons and their softening on single crystalline LaPt$_2$Si$_2$ via inelastic neutron scattering. From the temperature dependence of the phonon frequency in close proximity to the…
Advances in light sources and time resolved spectroscopy have made it possible to excite specific atomic vibrations in solids and to observe the resulting changes in electronic properties but the mechanism by which phonon excitation causes…