Related papers: Fermi surface and strong coupling superconductivit…
The Fermi surface is a central concept in the theory of metals. Even though the optimally doped high temperature superconductors exhibit an anomalous normal state, angle resolved photoemission spectroscopy (ARPES) has revealed a large Fermi…
We have performed an angle-resolved photoemission spectroscopy study of the new iron-based superconductor K0.8Fe1.7Se2 (Tc ~ 30 K). Clear band dispersion is observed with the overall bandwidth renormalized by a factor of 2.5 compared to our…
We have investigated the electronic states in quasi one dimensional (1D) CuO chains by microprobe Angle Resolved Photoemission Spectroscopy. We find that the quasiparticle Fermi surface consists of six disconnected segments, consistent with…
Obtaining the electronic structure of the newly discovered iron-based superconductors is the key to understanding the mechanism of their high-temperature superconductivity. We used angle-resolved photoemission spectroscopy (ARPES) to make…
We report electronic structure calculations for BaTi$_2$Sb$_2$O and discuss the results in relation to the observed superconductivity of this material when hole doped with Na. The Fermi surface shows several sheets. These include a nested…
We carried out high resolution angle-resolved photoemission measurements on the electronic structure and superconducting gap of K_0.68Fe_1.79Se_2 (T_c=32 K) and (Tl_0.45K_0.34)Fe_1.84Se_2 (T_c=28 K) superconductors. In addition to the…
We use high-resolution angle resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) to investigate the electronic structure of the charge density wave (CDW) system LaSb$_2$. This compound is among an interesting…
The superconducting gap is a pivotal character for a superconductor. While the cuprates and conventional phonon-mediated superconductors are characterized by distinct d-wave and s-wave pairing symmetry with nodal and nodeless gap…
Pnictogens and chalcogens are both viable anions for promoting Fe-based superconductivity and intense research activity in the related families has established systematic correlation between the Fe-anion height and the superconducting…
In order to clarify superconducting properties of BiS$_2$-based layered superconductors LaO$_{1-x}$F$_x$BiS$_2$, we evaluate the superconducting transition temperature $T_{\rm c}$ and analyze the gap function in a weak-coupling limit on the…
The origin of the monoclinic distortion and domain formation in the quasi two-dimensional layer compound NbTe$_2$ is investigated. Angle-resolved photoemission shows that the Fermi surface is pseudogapped over large portions of the…
The notion of a Fermi surface (FS) is one of the most ingenious concepts developed by solid state physicists during the past century. It plays a central role in our understanding of interacting electron systems. Extraordinary efforts have…
We show that the Fermi surface can survive the presence of extreme compositional disorder in the equiatomic alloy Ni$_{0.25}$Fe$_{0.25}$Co$_{0.25}$Cr$_{0.25}$. Our high-resolution Compton scattering experiments reveal a Fermi surface which…
The band structure and the Fermi surface of the recently discovered superconductor (EMIM)$_x$FeSe are studied within the density functional theory in the generalized gradient approximation. We show that the bands near the Fermi level are…
High resolution angle-resolved photoemission measurements have been carried out to study the electronic structure and superconducting gap of the (Tl$_{0.58}$Rb$_{0.42}$)Fe$_{1.72}$Se$_2$ superconductor with a T$_c$=32 K. The Fermi surface…
We use high resolution angle resolved photoemission spectroscopy and density functional theory with experimentally obtained crystal structure parameters to study the electronic properties of CaKFe4As4. In contrast to related CaFe2As2…
Despite the intense theoretical and experimental effort, an understanding of the superconducting pairing mechanism of the high-temperature superconductors is still lacking. An additional puzzle is the unknown connection between the…
The momentum distribution of the energy gap opening at the Fermi level of superconductors is a direct fingerprint of the pairing mechanism. While the phase diagram of the iron-based superconductors promotes antiferromagnetic fluctuations as…
In the pseudogap state of the high-Tc copper-oxide (cuprate) superconductors, angle-resolved photoemission (ARPES) measurements have seen an Fermi arc, i.e., an open-ended gapless section in the large Fermi surface, rather than a closed…
A detailed tight-binding analysis of the electron band structure of the CuO_2 plane of layered cuprates is performed within a sigma-band Hamiltonian including four orbitals - Cu3d_x^2-y^2, Cu4s, O2p_x, and O2p_y. Both the experimental and…