Related papers: Real Space Coulomb Interaction: A Pairing Glue for…
The ground state of K$_{0.8+x}$Fe$_{1.6+y}$Se$_2$ and other iron-based selenide superconductors are doped antiferromagnetic semiconductors. There are well defined iron local moments whose energies are separated from those of conduction…
The electron-hole states of semiconductor quantum dots are investigated within the framework of empirical tight-binding descriptions for Si, as an example of an indirect gap material, and InAs and CdSe as examples of typical III-V and II-VI…
We consider interaction-induced broken symmetry states of two Weyl semimetal surfaces with multiple Fermi-arc (FA) states. In the presence of inter- and intra-surface Coulomb interactions, multiple broken symmetries may emerge which coexist…
We study superconductivity of electron systems with both spin and pseudospin-1/2 degrees of freedom. By solving linearized gap equations, we derive a weak coupling criterion for the even-parity spin-singlet pseudospin-triplet pairing. It…
The BCS theory of superconductivity named electron-phonon interaction as a glue that overcomes Coulomb repulsion and binds fermions into pairs which then condense and superconduct. We review recent and not so recent works aiming to…
Superconductivity in cuprates is achieved by doping holes into a correlated charge-transfer insulator. While the correlated character of the parent insulator is now understood, there is no accepted theory for the "normal" state of the doped…
We investigate an unusual symmetry of Fe-based superconductors (FeSCs) and find novel superconducting pairing structures. FeSCs have a minimal translational unit cell composed of two Fe atoms due to the staggered positions of anions with…
Pseudogap formation is an ubiquitous phenomena in strongly-correlated superconductors, for example cuprates, heavy-fermion superconductors, and iron pnictides. As the system is cooled, an energy gap opens in the excitation spectrum before…
We consider the minimal two-band model for the Fe-based superconductors with a phenomenological pairing interaction which mimics short-range antiferromagnetic (AFM) fluctuations. Two superconducting (SC) gap solutions are found to exist…
We investigate interplay between magnetic fluctuations and superconductivity in the effective five-band Hubbard model for iron-oxypnictide superconductors on the basis of the fluctuation-exchange approximation. As for the normal-state…
I review recent works on the symmetry and the structure of the superconducting gap in Fe-based superconductors and on the underlying pairing mechanism in these systems. The experimental data on superconductivity show very rich behavior,…
Antiferromagnetic coupling between ferromagnetic layers has been observed for the first time in all-semiconductor superlattice structure EuS/PbS(001), by neutron scattering and magnetization measurements. Spin-dependent superlattice band…
The behavior of electrons in condensed matter systems is mostly determined by the repulsive Coulomb interaction. However, under special circumstances the Coulomb interaction can be effectively attractive, giving rise to electron pairing in…
We study the non-local superconducting pairing of two interacting Anderson impurities, which has an instability near the quantum critical point from the competition between the Kondo effect and an antiferromagnetic inter-impurity spin…
This work shows that a strongly correlated phase which is gapped to collective spin excitations but gapless to charge fluctuations emerges as a universal feature in one-dimensional fermionic systems obeying certain symmetries. Namely,…
When interacting electrons are confined to low-dimensions, the electron-electron correlation effect is enhanced dramatically, which often drives the system into exhibiting behaviors that are otherwise highly improbable. Superconductivity…
Superconductivity in intercalated graphite CaC6 and H under extreme pressure, in the framework of superconducting density functional theory, is discussed. A detailed analysis on how the electron-phonon and electron-electron interactions…
A key question in high temperature iron-based superconductivity is the mechanism by which the paired electrons minimize their strong mutual Coulomb repulsion. While electronically paired superconductors generally avoid the Coulomb…
Hole gases in planar germanium can have high mobilities in combination with strong spin-orbit interaction and electrically tunable g-factors, and are therefore emerging as a promising platform for creating hybrid…
We present a theoretical analysis of the effect of dielectric confinement on the Coulomb interaction in dielectrically modulated quantum structures. We discuss the implications of the strong enhancement of the electron-hole and…