Related papers: Transient gap generation in BaFe$_2$As$_2$ driven …
Since the discovery of high temperature superconductivity in iron pnictides in early 2008, many iron-based superconductors with different structures have been discovered, with the highest transition temperature to date being 57 K. By the…
The electronic structure and lattice vibrational frequencies of the newly discovered superconductors, LiFeAs and NaFeAs, are calculated within density functional theory. We show that in the vicinity of the Fermi energy, the density of…
Temperature and fluence dependence of the 1.55-eV optical transient reflectivity in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ was measured and analysed in the low and high excitation density limit. The effective magnitude of the superconducting…
AgCrSe$_2$ is an example of a super-ionic conductor that has recently attracted attention for its low thermal conductivity. Here we investigate the optical properties of AgCrSe$_2$ in the ordered phase between 14 K and 374 K using…
Inelastic light scattering studies on single crystal of electron-doped Ca(Fe0.95Co0.05)2As2 superconductor, covering the tetragonal to orthorhombic structural transition as well as magnetic transition at TSM ~ 140 K and superconducting…
Formation of electron pairs is essential to superconductivity. For conventional superconductors, tunnelling spectroscopy has established that pairing is mediated by bosonic modes (phonons); a peak in the second derivative of tunnel current…
The interplay between spin dynamics and lattice vibration has been suggested as an important part of the puzzle of high-temperature superconductivity. Here we report the strong interaction between spin fluctuation and phonon in SmFeAsO, a…
Raman studies on Ca4Al2O5.7Fe2As2 superconductor in the temperature range of 5 K to 300 K, covering the superconducting transition temperature Tc ~ 28.3 K, reveal that the Raman mode at ~ 230 cm-1 shows a sharp jump in frequency by ~ 2 %…
By interpreting various experimental data for the new high temperature FeAs type superconductors in terms of lattice mediated multi gap superconductivity, it is shown that these systems strongly resemble MgB2, however, with the distinction…
We report a detailed study of the electronic structure of the MgB$_{2}$ with different lattice constants by using the full-potential linearized augmented plane wave(FPLAPW) method. It is found that the lattice parameters have great effect…
We investigate the structural, electronic, and magnetic properties of the hypothetical compound BaFePn2 (Pn = As and Sb), which is isostructural to the parent compound of the high temperature superconductor LaFeAsO1-xFx. Using density…
BaFe$_2$As$_2$ is the parent compound for a family of iron-based high-temperature superconductors as well as a prototypical example of the spin-density wave (SDW) system. In this study, we perform an optical pump-probe study of this…
The nature of the pairing state in iron-based superconductors is the subject of much debate. Here we argue that in one material, the stoichiometric iron pnictide KFe2As2, there is overwhelming evidence for a d-wave pairing state,…
In this study, we conducted various magnetotransport measurements on Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ single crystals from which excess iron was sufficiently removed. Our results revealed that crossover from the incoherent to the coherent…
Charge, spin and lattice degrees of freedom are strongly entangled in iron superconductors. A neat consequence of this entanglement is the behavior of the A_{1g} As-phonon resonance in the different polarization symmetries of Raman…
Magnetic interactions are generally believed to play a key role in mediating electron pairing for superconductivity in iron arsenides; yet their character is only partially understood. Experimentally, the antiferromagnetic (AF) transition…
The magnetic moment in the parent phase of the iron-pnictide superconductors varies with composition even when the nominal charge of iron is unchanged. We propose the spin-lattice coupling due to the magneto-volume effect as the primary…
Magnons in antiferromagnetic insulators couple strongly to conduction electrons in adjacent metals. We show that this interfacial tie can lead to superconductivity in a tri-layer consisting of a metal sandwiched between two…
Various two-dimensional (2D) materials with graphene-like buckled structure emerge, and the $\beta$-phase AsP monolayer has been recently proposed to be thermodynamically stable from first-principles calculations. The studies of thermal…
We present ARPES data taken from the structurally simplest representative of iron-based superconductors, FeSe, in a wide temperature range. Apart from the variations related to the nematic transition, we detect very pronounced shifts of the…