Related papers: Hidden Fermi surface in K$_x$Fe$_{2-y}$Se$_2$: LDA…
We have studied the low-lying electronic structure of a new ThCr$_2$Si$_2$-type superconductor KNi$_2$Se$_2$ with angle-resolved photoemission spectroscopy. Three bands intersect the Fermi level, forming complicated Fermi surface topology,…
We generalize the dynamical-mean field (DMFT) approximation by including into the DMFT equations some length scale via a (momentum dependent) ``external'' self-energy \Sigma_k. This external self-energy describes non-local dynamical…
Using angle-resolved photoemission spectroscopy, we show that the recently-discovered surface state on SrTiO$_{3}$ consists of non-degenerate $t_{2g}$ states with different dimensional characters. While the $d_{xy}$ bands have quasi-2D…
The angle-resolved photoemission spectra of the superconductor (Ba$_{1-x}$K$_x$)Fe$_2$As$_2$ have been investigated both experimentally and theoretically. Our results explain the previously obscured origins of all salient features of the…
In our Nature paper, we reported observation of Fermi pocket in Bi_2(Sr_{2-x}La_x)CuO_{6+\delta} (La-Bi2201) by angle-resolved photoemission (ARPES) measurements. King et al. tried to assign the Fermi pocket we observed as due to an…
We have examined theoretically the electronic band structure and Fermi surface of tetragonal low-temperature superconductor Bi2Pd. Our main results are that (i) the Pd 4d and Bi 6p states determine the main peculiarities of the…
We have performed high-resolution angle-resolved photoemission spectroscopy on heavily overdoped KFe_2As_2 (transition temperature (Tc = 3 K). We observed several renormalized bands near the Fermi level with a renormalization factor of 2-4.…
We report measurements of the de Haas-van Alphen (dHvA) oscillation and a band structure calculation for the pnictide superconductor BaNi$_2$P$_2$, which is isostructural to BaFe$_2$As$_2$, the mother compound of the iron-pnictide…
Although nodeless superconducting gap has been observed on the large Fermi pockets around the zone corner in KxFe2-ySe2, whether its pairing symmetry is s-wave or nodeless d-wave is still under intense debate. Here we report an isotropic…
In conventional BCS superconductors, the quantum condensation of superconducting electron pairs is understood as a Fermi surface (FS) instability, in which the low-energy electrons are paired by attractive interactions. Whether this…
$\alpha$-FeSe, a prototype iron-chalcogenide superconductor, shows clear signatures of a strange incoherent normal state. Motivated thereby, we use LDA+DMFT to show how strong multi-band correlations generate a low-energy pseudogap in the…
We have performed high-resolution angle-resolved photoemission spectroscopy on the optimally-doped Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ compound and determined the accurate momentum dependence of the superconducting (SC) gap in four…
We report first-principles calculations of the k- and T-dependent superconducting gap Delta(k,T) in MgB2 and its manifestation in various measured quantities. Because the Fermi surface has disconnected sheets with different electron-phonon…
We studied the pairing instabilities in K$_x$Fe$_{2-y}$Se$_2$ using a two stage functional renormalization group (FRG) method. Our results suggest the leading and subleading pairing symmetries are nodeless $d_{x^2-y^2}$ and nodal extended…
We observe apparent hole pockets in the Fermi surfaces of single-layer Bi-based cuprate superconductors from angle-resolved photoemission (ARPES). From detailed low-energy electron diffraction measurements and an analysis of the ARPES…
We show that the Fermi surface (FS) in the antiferromagnetic phase of BaFe$_2$As$_2$ is composed of one hole and two electron pockets, all of which are three dimensional and closed, in sharp contrast to the FS observed by angle-resolved…
In order to understand the origin of superconductivity, it is crucial to ascertain the nature and origin of the primary carriers available to participate in pairing. Recent quantum oscillation experiments on high Tc cuprate superconductors…
We have performed an angle-resolved photoemission spectroscopy study of a new iron-based superconductor Sr4V2O6Fe2As2. While V 3d orbitals are found to be in a Mott insulator state and show an incoherent peak at ~ 1 eV below the Fermi…
We use high resolution angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) to investigate the electronic structure of trigonal phase ${\rm PtBi_2}$ (t-${\rm PtBi_2}$), a proposed Weyl semimetal that is…
We present an approach that combines the local density approximation (LDA) and the dynamical mean-field theory (DMFT) in the framework of the full-potential linear augmented plane waves (FLAPW) method. Wannier-like functions for the…