Related papers: Fermi surface topology and low-lying quasiparticle…
The electronic structure of the reentrant superconductor Eu(Fe$_{0.86}$Ir$_{0.14}$)$_{2}$As$_{2}$ (T$_c$ = 22 K) with coexisting ferromagnetic order (T$_M$ = 18 K) is investigated using angle-resolved photoemission spectroscopy (ARPES) and…
We examine the influence of the excess of interstitial Fe on the magnetic properties of Fe$_{1+y}$Te compounds. Because in iron chalcogenides the correlations are stronger than in the iron arsenides, we assume in our model that some of the…
The locally noncentrosymmetric heavy fermion superconductor CeRh$_2$As$_2$ has attracted considerable interests due to its rich superconducting phases, accompanied by a quadrupole density wave and pronounced antiferromagnetic excitations.…
We present different transport measurements up to fields of 29~T in the recently discovered heavy-fermion superconductor UTe$_{2}$ with magnetic field $H$ applied along the easy magnetization a-axis of the body-centered orthorhombic…
We report an angle-resolved photoemission investigation of optimally-doped Ca$_{0.33}$Na$_{0.67}$Fe$_2$As$_2$. The Fermi surface topology of this compound is similar to that of the well-studied Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ material,…
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…
In this review, we present a summary of experimental studies of magnetism in Fe-based superconductors. The doping dependent phase diagram shows strong similarities to the generic phase diagram of the cuprates. Parent compounds exhibit…
The emergence of nematic electronic states accompanied by a structural phase transition is a recurring theme in many correlated electron materials, including the high-temperature copper oxide- and iron-based superconductors. We provide…
An outstanding problem in the field of high-transition-temperature (high Tc) superconductivity is the identification of the normal state out of which superconductivity emerges in the mysterious underdoped regime. The normal state…
We uncover the low-energy spectrum of a t-J model for electrons on a square lattice of spin-1 iron atoms with 3dxz and 3dyz orbital character by applying Schwinger-boson-slave-fermion mean-field theory and by exact diagonalization of one…
Topological superconductors should be able to provide essential ingredients for quantum computing, but are very challenging to realize. Spin-orbit interaction in iron-based superconductors opens the energy gap between the $p$-states of…
The field-reentrant (field-reinforced) superconductivity on ferromagnetic superconductors is one of the most interesting topics in unconventional superconductivity. The enhancement of effective mass and the induced ferromagnetic…
Pairing symmetry in oxypnictides, a new family of multiband high-Tc superconductors, is partially imposed by the positions of multiple Fermi pockets, which itself can give rise to new order parameters, such as s+,- states or the state of…
I review works on Fe-based superconductors which depart from a metal with well defined Fermi surfaces and Fermi liquid-type quasiparticles. I consider normal state instabilities -- SDW magnetism and nematic order, and superconductivity, all…
Emergent electronic phenomena in iron-based superconductors have been at the forefront of condensed matter physics for more than a decade. Much has been learned about the origin and intertwined roles of ordered phases, including nematicity,…
We report quantum oscillation measurements on CaFe2As2 under strong magnetic fields- recently reported to become superconducting under pressures of as little as a kilobar. The largest observed carrier pocket occupies less than 0.05 % of the…
The superconducting state of iron pnictides and chalcogenides exists at the border of antiferromagnetic order. Consequently, these materials could provide clues about the relationship between magnetism and unconventional superconductivity.…
Recent observation of pressure induced second superconducting phase in AyFe2-xSe2 [A=K, (Tl,Rb)] calls for the models of superconductivity that are rich enough to allow for multiple superconducting phases. We propose the model where…
The iron-based superconductors are characterized by multiple-orbital physics where all the five Fe 3$d$ orbitals get involved. The multiple-orbital nature gives rise to various novel phenomena like orbital-selective Mott transition,…
It is shown that, in the presence of a moderately strong C_4 symmetry breaking (which could be produced either by lattice orthorhombicity or the presence of an electron nematic phase), a weak, period 4, unidirectional charge density wave…