Related papers: Superconductivity in Undoped BaFe2As2 by Tetrahedr…
The discovery of a new family of high Tc materials, the iron arsenides (FeAs), has led to a resurgence of interest in superconductivity. Several important traits of these materials are now apparent, for example, layers of iron tetrahedrally…
Emergent superconductivity is strongly correlated with the symmetry of local atomic configuration in the parent compounds of iron-based superconductors. While chemical doping or hydrostatic pressure can change the local geometry, these…
The recently discovered Fe-based superconductor (FeBS) LaFe2As2 seems to break away from an established pattern that doping FeBS beyond 0.2e/Fe destroys superconductivity. LaFe2As2 has an apparent doping of 0.5e, yet superconducts at 12.1…
Quantum transitions in Fe-based systems are believed to involve spin, charge and nematic fluctuations. Complex structural phase diagram in these materials often emphasizes importance of covalency in their exotic properties, which is…
We report on doping dependencies of structural parameters and superconducting transition temperatures in the solid solution (Ba1-xKx)Fe2As2. As the main effect of doping on the crystal structure, we find linear decreasing As-Fe-As bond…
High-resolution x-ray diffraction measurements reveal an unusually strong response of the lattice to superconductivity in Ba[Fe(1-x)Cox]2As2. The orthorhombic distortion of the lattice is suppressed and, for Co-doping near x = 0.063, the…
Unconventional superconductivity often intertwines with various forms of order, such as the "nematic" order which breaks the rotational symmetry of the lattice. Investigation of these ordered phases sheds crucial light on the…
The recent discovery and subsequent developments of FeAs-based superconductors have presented novel challenges and opportunities in the quest for superconducting mechanisms in correlated-electron systems. Central issues of ongoing studies…
On experimental side, BaFe$_2$As$_2$ without doping has been made superconducting by applying appropriate pressure (2-6 GPa). Here, we use a full-potential linearized augmented plane wave method within the density-functional theory to…
BaFe2As2 exhibits properties characteristic of the parent compounds of the newly discovered iron (Fe)-based high-TC superconductors. By combining the real space imaging of scanning tunneling microscopy/spectroscopy (STM/S) with momentum…
Direct quantitative correlations between the orbital order and orthorhombicity is achieved in a number of Fe-based superconductors of 122 family. The former (orbital order) is calculated from first principles simulations using…
Among numerous hypotheses, recently proposed to explain superconductivity in iron-based superconductors [1-9], many consider Fermi surface (FS) nesting [2, 4, 8, 10] and dimensionality [4, 9] as important contributors. Precise determination…
We have performed the first-principles electronic structure calculation for the novel superconductor Ca4Al2O6Fe2As2 which has the smallest a lattice parameter and the largest As height from the Fe plane among the Fe-As superconductors. We…
Much remains unknown of the microscopic origin of superconductivity when it materializes in atomically disordered systems as in amorphous alloys (1) or in crystals riddled with defects(2). A manifestation of this conundrum is envisaged in…
The discovery of high-temperature superconductivity in Fe-based compounds [1,2] has triggered numerous investigations on the interplay between superconductivity and magnetism [3] and, more recently, on the enhancement of transition…
We have performed angle-resolved photoemission spectroscopy on a heterostructure consisting of topological insulator Bi2Te3 and iron chalcogenide FeTe fabricated on SrTiO3 substrate by molecular-beam-epitaxy technique. This system was…
The Fe-based superconducting KxFe2-ySe2 (0.6 {\leg} x {\leg} 1, 0.2{\leg} y {\leg} 0.4) compounds, unlike the well-known RFe2As2 (R = Ba, Sr, Ca) superconductors, contain complex structural features and notable physical properties, such as…
We present detailed electronic structure calculations for CaFe2As2. We investigate in particular the `collapsed' tetragonal and orthorhombic regions of the temperature-pressure phase diagram and find properties that distinguish CaFe2As2…
We report structurally tuned superconductivity in KxFe2-ySe2-zSz (0<=z<=2) phase diagram. Superconducting Tc is suppressed as S is incorporated into the lattice, eventually vanishing at 80% of S. The magnetic and conductivity properties can…
Using {\it ab initio} molecular dynamics we investigate the electronic and lattice structure of $A$Fe$_2$As$_2$ ($A$=Ca, Sr, Ba) under pressure. We find that the structural phase transition (orthorhombic to tetragonal symmetry) is always…