Related papers: Unconventional pairing in single FeSe layers

Charge transfer and electron-phonon coupling (EPC) are proposed to be two important constituents associated with enhanced superconductivity in the single unit cell FeSe films on oxide surfaces. Using high-resolution electron energy loss…

Photo-excitation is a very powerful way to instantaneously drive a material into a novel quantum state without any fabrication, and variable ultrafast techniques have been developed to observe how electron-, lattice-, and spin-degrees of…

We present a systematic photoemission study of the newly discovered high Tc superconductor class (Sr/Ba)1-xKxFe2As2. By utilizing a unique photon energy range and scattering geometry we resolve the details of the single particle dynamics of…

We have performed an extensive ab initio LDA and LSDA+U calculations of electronic structure of newly discovered high-temperature superconducting series ReO(1-x)F(x)FeAs (Re=La,Ce, Pr, Nd, Sm and hypothetical case of Re=Y). In all cases we…

Since conventional superconductivity is mediated by phonons, their role in the mechanism of high temperature superconductivity has been considered very early after the discovery of the cuprates. The initial consensus was that phonons could…

Exploration of new superconductors has always been one of the research directions in condensed matter physics. We report here a new layered heterostructure of [(Fe,Al)(OH)2][FeSe]1.2, which is synthesized by the hydrothermal ion-exchange…

Fundamental upper bounds on the electron-phonon interaction strength and superconducting transition temperature $T_c$ in metals are established based on the intrinsic instability of the equilibrium between electrons and the crystal lattice…

In paired Fermi systems, strong many-body effects exhibit in the crossover regime between the Bardeen-Cooper-Schrieffer (BCS) and the Bose-Einstein condensation (BEC) limits. The concept of the BCS-BEC crossover, which is studied…

The detailed temperature dependence of the infrared-active mode in Fe$_{1.03}$Te ($T_N\simeq 68$ K) and Fe$_{1.13}$Te ($T_N\simeq 56$ K) has been examined, and the position, width, strength, and asymmetry parameter determined using an…

Recent superconducting transition temperatures (Tc) over 100 K for monolayer FeSe on SrTiO3 have renewed interest in the bulk parent compound. In KCl:AlCl3 flux-transport-grown crystals of FeSe0.94Be0.06, FeSe0.97Be0.03 and, for comparison,…

Many investigators have joined the search for a bosonic glue which is hypothecated to be the mechanism which binds the electron pairs in the cuprate high Tc superconductors, often referring to the Eliashberg formalism which was developed to…

YPtBi, a topological semimetal with very low carrier density, was recently found to be superconducting below $T_\mathrm{c} = 0.77$\,K. In the conventional theory, the nearly vanishing density of states around the Fermi level would imply a…

The pairing mechanism in iron-based superconductors is the subject of ongoing debate. Proximity to an antiferromagnetic phase suggests that pairing is mediated by spin fluctuations, but orbital fluctuations have also been invoked. The…

We analyze Cooper pairing instabilities in strongly driven electron-phonon systems. The light-induced non-equilibrium state of phonons results in a simultaneous increase of the superconducting coupling constant and the electron scattering.…

In the quest for high temperature superconductors, the interface between a metal and a dielectric was proposed to possibly achieve very high superconducting transition temperature ($T_c$) through interface-assisted pairing. Recently, in…

The iron-based LaFeAsO$_{1-x}$F$_x$ recently discovered by Hosono's group is a fresh theoretical challenge as a new class of high-temperature superconductors. Here we describe the electronic structure of the material and the mechanism of…

We describe high-Tc superconductivity in layered materials within a BCS theory as a BEC of massless-like Cooper pairons satisfying a linear dispersion relation, and propagating within quasi-2D layers of finite width defined by the charge…

Unlike the parent phases of the iron-arsenide high Tc superconductors, undoped FeSe is not magnetically ordered and exhibits superconductivity with Tc~9K. Equally surprising is the fact that applied pressure dramatically enhances the modest…

Superconductivity of iron chalocogenides is strongly enhanced under applied pressure yet its underlying pairing mechanism remains elusive. Here, we present a quantum oscillations study up to 45 T in the high-$T_c$ phase of tetragonal…

In contrast to bulk FeSe superconductor, heavily electron-doped FeSe-derived superconductors show relatively high Tc without hole Fermi surfaces and nodal superconducting gap structure, which pose great challenges on pairing theories in the…