Related papers: s+is superconductivity with incipient bands: dopin…
We study the spin-fluctuation-mediated $s\pm$-wave superconductivity in the bilayer Hubbard model with vertical and diagonal interlayer hoppings. As in the two-leg ladder model with diagonal hoppings, studied previously by the present…
We study the two-band model of spinless fermions in one dimension for weak repulsive interactions. In this case, the model is equivalent to the weakly interacting spinless two-leg ladder. We obtain analytic expressions for the…
We studied the doping and temperature (T) dependence of the infrared (IR) response of Ba(Fe1-xCox)2As2 single crystals. We show that a weak band around 1000 cm-1, that was previously interpreted in terms of interaction of the charge…
A major impediment to solving the problem of high-$T_c$ superconductivity is the ongoing confusion about the magnitude, structure and doping dependence of the superconducting gap, $\Delta_0$, and of the mysterious pseudogap found in…
We investigate the properties of cuprate superconductors subject to applied current, using modified Gutzwiller projected d-wave BCS states. The parent states include quasiparticle and quasihole pockets, of variationally determined size,…
Within the two-orbital model for BiS$_{2}$-based superconductors, the effect from a single nonmagnetic impurity scattering on the superconducting-state is investigated in terms of the T-matrix approach. By considering three kinds of the…
Transition metal dichalcogenides offer unprecedented versatility to engineer 2D materials with tailored properties to explore novel structural and electronic phase transitions. In this work, we present the atomic-scale evolution of the…
The nature of superconductivity in monolayer transition metal dichalcogenides is still an object of debate. It has already been argued that repulsive Coulomb interactions, combined with the disjoint Fermi surfaces around the $K$, $K'$…
We study two mechanisms for enhancing the superconducting transition temperature Tc by nonmagnetic disorder in both conventional (sign-preserving gaps) and unconventional (sign-changing gaps) superconductors (SC). In the first scenario,…
The impurity effects on the transition temperature Tc and the isotope effect are examined in multiband superconductors with magnetic and nonmagnetic impurities, where the effect of Coulomb repulsion is considered. It is shown that an…
A dome-shaped phase diagram of superconducting critical temperature upon doping is often considered as a hallmark of unconventional superconductors. This behavior, observed in two-dimensional electron gases in $\mathrm{SrTiO}_3$-based…
Bulk superconductivity in a topological semimetal is a first step towards realizing topological superconductors, which can host Majorana fermions allowing us to achieve quantum computing. Here, we report superconductivity and compensation…
One of the ultimate goals of the study of iron-based superconductors is to identify the common feature that produces the high critical temperature (Tc). In the early days, based on a weak-coupling viewpoint, the nesting between hole- and…
The high-transition-temperature (high-Tc) superconductivity discovered recently in iron pnictides is analyzed within a perturbation theory. Specifically, the probable pairing symmetry, the doping dependence of the transition temperature and…
The interplay of different emergent phenomena -- superconductivity (SC) and domain formation -- appearing on different spatial and energy scales are investigated using high-resolution scanning tunneling spectroscopy (STS) in the…
We report X-ray diffraction, magnetization and transport measurements for polycrystalline samples of the new layered superconductor Bi4-xAgxO4S3 (0<x<0.2). The superconducting transition temperature (TC) decreases gradually and finally…
We present a novel route for attaining unconventional superconductivity (SC) in a strongly correlated system without doping. In a simple model of a correlated band insulator (BI) at half-filling we demonstrate, based on a generalization of…
Based on a combination of X-ray diffraction, electrical transports, magnetic susceptibility, specific heat and pressure effect measurements, we report a series of BiS$_{2}$-based Sr$_{1-x}$Pr$_{x}$FBiS$_{2}$ superconductors with the maximum…
We show that in two-band $s$-wave superfluids it is possible to induce quantum phase transitions (QPTs) by tuning intraband and interband $s$-wave interactions, in sharp contrast to single-band $s$-wave superfluids, where only a crossover…
The isovalent-substituted iron pnictide compound SrFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and…