Learn More
The iron pnictide and chalcogenide compounds are a subject of intensive investigations owing to their surprisingly high temperature superconductivity. They all share the same basic building blocks, but there is significant variation in their physical properties, such as magnetic ordered moments, effective masses, superconducting gaps and transition(More)
The symmetry of thewavefunction describing the Cooper pairs is one of the most fundamental quantities in a superconductor, but for iron-based superconductors it has proved to be problematic to determine, owing to their complex multi-band nature1–3. Here we use a first-principles many-body method, including the two-particle vertex function, to study the spin(More)
To investigate the effect of exogenous Spermidine (Spd) and Spermine (Spm) on drought-induced damage to seedlings of Cerasus humili, relative water content (RWC), malondialdehyde content, relative electrolyte leakage, superoxide (O2 −, SOD) generation rate, hydrogen peroxide (H2O2), endogenous polyamines (PAs), antioxidant enzymes [SOD and peroxidase (POD)](More)
When either electron or hole doped at concentrations x approximately 0.1, the LaFeAsO family displays remarkably high temperature superconductivity with Tc up to 55 K. In the most energetically stable Q-->M=(pi,pi,0) antiferromagnetic (AFM) phase comprised of tetragonal-symmetry breaking alternating chains of aligned spins, there is a deep pseudogap in the(More)
We perform realistic first-principles calculations of iron chalcogenides and ruthenate-based materials to identify experimental signatures of Hund’s-coupling-induced correlations in these systems. We find that FeTe and KxFe2−ySe2 display unusual orbital-dependent fractional power-law behavior in their quasiparticle self-energy and optical conductivity, a(More)
We show that the electron-phonon coupling (EPC) in many materials can be significantly underestimated by the standard density-functional theory (DFT) in the local-density approximation (LDA) due to large nonlocal correlation effects. We present a simple yet efficient methodology to evaluate the realistic EPC, going beyond the LDA by using more advanced and(More)
Widespread adoption of superconducting technologies awaits the discovery of new materials with enhanced properties, especially higher superconducting transition temperatures T(c). The unexpected discovery of high T(c) superconductivity in cuprates suggests that the highest T(c)s occur when pressure or doping transform the localized and moment-bearing(More)
We use the combination of density functional theory and dynamical mean field theory (DFT+DMFT) [S1] as implemented in Ref. S2, which is based on the fullpotential linear augmented plane wave method implemented in Wien2K [S3], to carry out our first principles calculations. The electronic charge is computed selfconsistently on DFT+DMFT density matrix. The(More)
We show that the numerical renormalization group is a viable multi-band impurity solver for dynamical mean-field theory (DMFT), offering unprecedented real-frequency spectral resolution at arbitrarily low energies and temperatures. We use it to obtain a numerically exact DMFT solution to the Hund metal problem for a three-band model on a Bethe lattice at(More)