Related papers: Impurities and orbital dependent superconductivity…
In the theoretical analyses of impurity effects in superconductors the assumption is usually made that all quantities, except for the Green functions, are slowly varying functions of energy. When this so-called Fermi Surface Restricted…
Materials with strongly correlated electrons exhibit physical properties that are often difficult to predict as they result from the interactions of large numbers of electrons combined with several quantum degrees of freedom. The layered…
Impurities with the pronounced forward scattering (FS impurities) change analytical properties of the quasiparticle Green's function substantially compared to the isotropic scattering. By assuming that the superconducting pairing is due to…
Nodal superconductivity is observed in LiFeP while its counterpart LiFeAs with similar topology and orbital content of the Fermi surfaces is a nodeless superconductor. We explain this difference by solving, in the two-Fe Brillouin zone, the…
An arbitrarily small concentration of impurities can affect the spin Hall conductivity in a two-dimensional semiconductor system. We develop a Boltzmann-like equation that can be used for impurity scattering with arbitrary angular…
We study the presence of impurity bound states within a five-band Hubbard model relevant to iron-based superconductors. In agreement with earlier studies, we find that in the absence of Coulomb correlations there exists a range of repulsive…
The coexistence of ferromagnetism and superconductivity in RuSr$_2$GdCu$_2$O$_8$ was reported both from experiments (by Tallon et. al.) and first-principles calculations (by Pickett et. al.). Here we report that our first-principles…
One approach to probe the still controversial superconductivity in Sr$_2$RuO$_4$ is to apply external perturbations that break the underlying tetragonal crystalline symmetry. Chiral $p_x+ip_y$ and $d_{xz}+id_{yz}$ states respond to such…
Multiband superconductivity with dominant two-gap features are recently proposed to challenge the earlier accepted nodal $d$-wave pairing in the first unconventional superconductor CeCu$_{2}$Si$_{2}$. Here we obtain multiband Fermi-surface…
The mean-field study of the stripe phases of t-t'-U Hubbard model confirms formation of the "impurity" subbands of states localized on domain walls. For bond-aligned stripes it is shown that segments of the Fermi surfaces (FS) in antinodal…
A major puzzle about the nature of the iron-based superconductivity appears in the case of the alkaline iron selenides. Compared to the iron pnictides, these systems have only electron Fermi pockets (i.e. no hole Fermi pockets) but…
The possible superconducting states of strontium ruthenate (Sr$_2$RuO$_4$) are organized into irreducible representations of the point group $D_{4h}$, with a special emphasis on nodes occurring within the superconducting gap. Our analysis…
Sr$_2$RuO$_4$, an unconventional superconductor, is known to possess an incommensurate spin density wave instability driven by Fermi surface nesting. Here we report a static spin density wave ordering with a commensurate propagation vector…
We calculate frequency and temperature dependence of the anomalous ac Hall conductivity induced by impurity scattering in a chiral px+ipy superconductor, such as Sr2RuO4, with spontaneous time-reversal-symmetry breaking in the absence of an…
We study impurity bound states and impurity-induced order in the superconducting state of LiFeAs within a realistic five-band model based on the band structure and impurity potentials obtained from density functional theory (DFT). In…
Recent discovery of superconductivity at a transition temperature of $73$K in the doped layered compound Ba$_{2}$CuO$_{3+x}$ for $x\sim 0.2$ has generated a lot of interest. Experiments in this alternately stacked oxygen octahedral and…
The structure of the order parameter and the excitation spectrum are investigated for isolated impurities in d-wave superconductors. Atomic scale impurities, or defects, scatter quasiparticles and lead to local suppression (pair-breaking)…
The quasi-2D metal Sr$_2$RuO$_4$ is one of the best characterized unconventional superconductors, yet the nature of its superconducting order parameter is still highly debated. This information is crucial to determine the pairing mechanism…
We present a comprehensive angle-resolved photoemission spectroscopy study of Ca$_{1.8}$Sr$_{0.2}$RuO$_4$. Four distinct bands are revealed and along the Ru-O bond direction their orbital characters are identified through a light…
Impurity effects are probes for revealing an unconventional property in superconductivity. We study effects of non-magnetic impurities, in a 2D topological superconductor with s-wave pairing, the Rashba spin-orbit coupling, and the Zeeman…