Related papers: Superconductivity without magnetism in LiFeAs
For a newly discovered iron-based high $T_c$ superconductor LaFeAsO$_{1-x}$F$_x$, we have constructed a minimal model, where inclusion of all the five Fe $d$ bands is found to be necessary. Random-phase approximation is applied to the model…
Sr2RuO4 is at present the best candidate for being a superconducting analogue of the triplet superfluidity in ^3He. This material is a good (albeit correlated) Fermi liquid in the normal state and an exotic superconductor below Tc. The…
Despite the fact that 1111-type iron arsenides hold the record transition temperature of iron-based superconductors, their electronic structures have not been studied much because of the lack of high-quality single crystals. In this study,…
We consider the electric conductivity in normal metals in presence of a strong magnetic field. It is assumed here that the Fermi surface of a metal has rather complicated form such that different types of quasiclassical electron…
The Fermi surface of most hole-doped cuprates is close to a Van Hove singularity at the M point. A two-dimensional electronic system, whose Fermi surface is close to a Van Hove singularity shows a variety of weak coupling instabilities. It…
We report detailed measurements of the de Haas-van Alphen (dHvA) effect in BaFe_2P_2 which is the end member of the superconducting series, BaFe_2(As_{1-x}P_x)_2. Using high purity samples we are able to observe dHvA oscillations from all…
We prove regularity properties of the self-energy, to all orders in perturbation theory, for systems with singular Fermi surfaces which contain Van Hove points where the gradient of the dispersion relation vanishes. In this paper, we show…
A crucial step in revealing the nature of unconventional superconductivity is to investigate the symmetry of the superconducting order parameter. Scanning tunneling spectroscopy has proven a powerful technique to probe this symmetry by…
The iron-based superconductor FeSe has attracted much recent attention because of its simple crystal structure, distinct electronic structure and rich physics exhibited by itself and its derivatives. Determination of its intrinsic…
The electronic structure, stability, electron phonon coupling and superconductivity of the non-oxide perovskite MgCNi$_3$ are studied using density functional calculations. The band structure is dominated by a Ni $d$ derived density of…
The Fermi surface pockets that lie at the corner of the two-iron Brillouin zone in heavily electron-doped iron selenide superconductors are accounted for by an extended Hubbard model over the square lattice of iron atoms that includes the…
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…
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…
Following the discovery of the Fe-pnictide superconductors, LDA band structure calculations showed that the dominant contributions to the spectral weight near the Fermi energy came from the Fe 3d orbitals. The Fermi surface is characterized…
The thermal conductivity k of the iron-arsenide superconductor LiFeAs (Tc ~ 18K) was measured in single crystals at temperatures down to T~50mK and in magnetic fields up to H=17T, very close to the upper critical field Hc2~18T. For both…
Motivated by the recent contradiction of the superconducting pairing symmetry in the angle-resolved photoemission spectra (ARPES) and the nuclear magnetic resonance (NMR) data in the FeAs superconductors, we present the theoretical results…
We have performed high resolution angle-resolved photoemission measurements on superconducting electron-doped NaFe$_{0.95}$Co$_{0.05}$As ($T_{c}\sim$18 K). We observed a hole-like Fermi surface around the zone center and two electron-like…
The key feature of the Fe-based superconductors is their quasi 2D multiband Fermi surface. By relating the problem to a negative U Hubbard model and its superconducting ground state, we show that the defining instability of such a Fermi…
Based on density functional calculations, the relationship between magnetism or superconductivity and electronic states around Fermi level were derived, and the location of the Fermi level in nonmagnetic "form" of Laves-phase compounds is…
Unconventional superconductivity in iron pnictides and chalcogenides has been suggested to be controlled by the interplay of low-energy antiferromagnetic spin fluctuations and the particular topology of the Fermi surface in these materials.…