I review theoretical ideas and implications of experiments for the gap structure and symmetry
of the Fe-based superconductors. Unlike any other class of unconventional …

Almost a decade has passed since the serendipitous discovery of the iron-based high
temperature superconductors (FeSCs) in 2008. The fact that, as in the copper oxide high …

We investigate topological properties in the Fe (Te, Se) thin films. We find that the single
layer FeTe 1− x Se x has nontrivial Z 2 topological invariance which originates from the …

We construct the symmetry adapted low-energy effective Hamiltonian for the electronic
states in the vicinity of the Fermi level in iron-based superconductors. We use Luttinger's …

Single-layer FeSe films with an extremely expanded in-plane lattice constant of 3.99±0.02 Å
are fabricated by epitaxially growing FeSe/Nb: SrTiO 3/KTaO 3 heterostructures and studied …

We consider the nanoscale electronic phase separation in a wide class of different
materials, mostly in strongly correlated electron systems. The phase separation turns out to …

A distinct electronic structure was observed in the single-layer FeSe which shows
surprisingly high-temperature superconductivity over 65 K. Here, we demonstrate that the …

We performed a high-energy resolution angle-resolved photoemission spectroscopy
investigation of overdoped Ba 0.1 K 0.9 Fe 2 As 2 with T c= 9 K. The Fermi surface topology …

In high-temperature cuprate superconductors, it is now generally agreed that
superconductivity is realized by doping an antiferromagnetic Mott (charge transfer) insulator …

Although a nodeless superconducting gap has been observed on the large Fermi pockets
around the zone corner in K x Fe 2− y Se 2, whether its pairing symmetry is s wave or …