Related papers: The Tc amplification by quantum interference effec…

A short review of the optical and far-infrared measurements on MgB$_{2}$ is given. Multiband and multigap effects are analyzed by comparing optical properties with other experiments and {\em ab initio} calculations. The covered topics are:…

The discovery of superconductivity in MgB$_2$ (\(T_c = 39\) K) \cite{nagamatsu2001superconductivity} established metal diborides (MB$_2$) as a promising class of conventional superconductors. Recent advances in fabrication techniques have…

A relatively high critical temperature, Tc, approaching 40 K, places the recently-discovered superconductor magnesium diboride (MgB2) intermediate between the families of low- and copper-oxide-based high-temperature superconductors (HTS).…

First principles FLMTO-GGA electronic structure calculations of the new medium-$T_C$ superconductor (MTSC) $MgB_2$ and related diborides indicate that superconductivity in these compounds is related to the the existence of $p_{x,y}$-band…

We report scanning tunneling spectroscopy imaging of the vortex lattice in single crystalline MgB2. By tunneling parallel to the c-axis, a single superconducting gap (Delta = 2.2 meV) associated with the pi-band is observed. The vortices in…

Several theoretical analyses of the two superconducting energy gaps of magnesium diboride, $\Delta_\pi$ and $\Delta_\sigma$, predict substructures within each energy gap, rather than two pure numbers. Recent experiments have revealed…

High-temperature cuprate superconductors have been known to exhibit significant pressure effects. In order to fathom the origin of why and how Tc is affected by pressure, we have recently studied the pressure effects on Tc adoptig a model…

We present a systematic study of the response properties of two-band (multi-gap) superconductors with spin-singlet (s-wave) pairing correlations, which are assumed to be caused by both intraband (\lambda_{ii}, i=1,2) and interband…

We utilize the van de Pauw technique combined with Density Functional Theory to show that an external voltage applied to superconducting AlB2-type compounds, such as MgB2 and Mg(B1.9C0.1), effects substantive changes in transition…

Results of FLMTO-GGA (full-potential linear muffin-tin orbital -- generalized gradient approximation) calculations of the band structure and boron electric field gradients (EFG) for the new medium-T$_c$ superconductor (MTSC), MgB$_2$, and…

We study the effects of interband pairing in two-band s-wave and d-wave superconductors with D4h symmetry in both time-reversal invariant as well as time-reversal symmetry breaking states. The presence of interband pairing qualitatively…

The two gaps in a two-band clean s-wave superconductor are evaluated self-consistently within the quasiclassical Eilenberger weak-coupling formalism with two in-band and one inter-band pairing potentials. Superfluid density, free energy and…

Irradiation with Pb ions was used to study the effect of disorder on the in-plane London penetration depth, $\lambda(T)$, in single crystals of Ba(Fe$_{1-x}$T$_x$)$_2$As$_2$ (T=Co, Ni). An increase of the irradiation dose results in a…

Over the past 14 years MgB2 has gone from a startling discovery to a promising, applied superconductor. In this article we present a brief overview of the synthesis and the basic superconducting properties of this remarkable compound. In…

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…

The optical conductivity of MgB$_2$ has been determined on a dense polycrystalline sample in the spectral range 6 meV - 4.6 eV using a combination of ellipsometric and normal incidence reflectivity measurements. $\sigma_{1}(\omega)$…

(Abridged abstract) Alloyed MgB2 differs from pure forms in that diffusion is needed to distribute the alloying elements homogeneously. Williamson-Hall analyses of x-ray diffraction peaks showed that Mg1-xAlxB2 samples made by a typical…

We report a systematic study of the normal-state and superconducting properties of single crystal Pb$_{1-x}$Sn$_{x}$TaSe$_{2}$ $(0\leq x \leq 0.23)$. Sn doping enhances the superconducting temperature $T_{c}$ up to 5.1 K while also…

Cryogenic scanning tunneling microscopy and magnetization measurements were used to study the superconducting properties of MgB_2. The magnetization measurements show a sharp superconductor transition onset at T_c = 38.5 K, in agreement…

We show from a bond valence sum correlation that very high superconducting $ T_{c} $ values should be found in optimally hole-doped infinite-layer ACuO$ _{2} $ cuprates - up to 160~K for A = Ba. The projected increase in $ T_{c} $ across…