Related papers: Multiband superconductivity in high pressure sulfu…
The superconducting state in Carbonaceous Sulfur Hydride (C-S-H) system is characterized by the record-high critical temperature of $288$~K experimentally observed at $\sim$267 GPa. Herein, we determined the properties of the \mbox{C-S-H}…
We show on a few examples of one-band materials with spheroidal Fermi surfaces and anisotropic order parameters that anisotropies $\gamma_H$ of the upper critical field and $\gamma_\lambda$ of the London penetration depth depend on…
The angular and temperature dependence of the upper critical field Hc2 in MgB2 was determined from torque magnetometry measurements on single crystals. The Hc2 anisotropy gamma_H was found to decrease with increasing temperature, in…
First-principles calculations were carried out to provide a chemical basis for proposed structures associated with the recently reported room-temperature superconductivity in a carbonaceous sulfur hydride material under pressure.…
A recent theory of the disorder-dependent slope of the upper critical field, $H_{c2}$, at the superconducting transition temperature, $T_{c}$, is extended to multiband superconductors aiming at iron-based superconductors, considering two…
We present a Ginzburg-Landau theory for a two-band superconductor with emphasis on MgB$_{2}$. Experiments are proposed which lead to identification of the possible scenarios: whether both $\sigma $- and $\pi $-bands superconduct or $\sigma…
We evaluate accurate low-field/low-temperature asymptotics of the thermal conductivity perpendicular to magnetic field for one-band and two-band s-wave superconductors using Keldysh-Usadel formalism. We show that heat transport in this…
The microscopic superconductivity theory in MgB2 systems in the magnetic fields directed parallel and perpendicular to the plane (ab) is built. The two energy bands of different dimensions overlapping on the Fermi surface (two-dimensional…
We solve the coupled gap equations for the $\sigma$- and $\pi$-bands of MgB$_2$ in the vortex state and calculate the resulting field dependencies of the specific heat coefficient $\gamma$ and the thermal conductivity $\kappa $. The crucial…
We have performed low-temperature specific-heat measurements in magnetic fields for a single crystal UBe13. It has been observed that our sample exhibits a superconducting transition at an intermediate temperature between previously…
The newly discovered iron pnictide superconductors apparently present an unusual case of interband-channel pairing superconductivity. Here we show that, in the limit where the pairing occurs within the interband channel, several surprising…
The upper critical fields, $H_{c2}$($T$), of single crystals of the superconductor Ca$_{10}$(Pt$_{4-\delta}$As$_{8}$)((Fe$_{0.97}$Pt$_{0.03}$)$_{2}$As$_{2}$)$_{5}$ ($\delta$ $\approx$ 0.246) are determined over a wide range of temperatures…
We present simple qualitative estimates for the maximal superconducting transition temperature, which may be achieved due to electron - phonon coupling in Eliashberg-McMillan theory. It is shown that in the limit of very strong coupling the…
Temperature dependence of the upper critical magnetic field (Hc2) of single crystalline FeTe0.5Se0.5 (Tc = 14.5 K) have been determined by tunnel diode oscillator-based measurements in magnetic fields of up to 55 T and temperatures down to…
The discovery of high-temperature superconductivity in compressed H3S by Drozdov and co-workers (A. Drozdov, et. al., Nature 525, 73 (2015)) heralded a new era in superconductivity. To date, the record transition temperature of Tc = 260 K…
Experimental support is found for the multiband model of the superconductivity in the recently discovered system MgB2 with the transition temperature Tc = 39 K. By means of Andreev reflection evidence is obtained for two distinct…
We report a detailed low-temperature thermodynamic investigation (heat capacity and magnetization) of the superconducting state of KFe2As2 for H || c axis. Our measurements reveal that the properties of KFe2As2 are dominated by a relatively…
Temperature dependence of the upper critical field Hc2 (T) for the superconducting magnesium diboride, MgB2, is studied in the vicinity of Tc by using a two-band Ginzburg-Landau (G-L) theory. The temperature dependence of Hc2 (T) near Tc…
We investigate the upper critical field in a dirty two-band superconductor within quasiclassical Usadel equations. The regime of very high anisotropy in the quasi-2D band, relevant for MgB$_{2}$, is considered. We show that strong…
The temperature dependencies of the coupled superconducting gaps, observed in Fe-As based superconducting compounds is calculated and a universal temperature scaling observed which is only present if the coupled order parameters both have…