Related papers: Multiband superconductors close to a 3D-2D electro…
The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta1=2.3 meV and Delta2=7.1 meV. Different spectral weights of the partial…
We propose a two band model for superconductivity. It turns out that the simplest nontrivial case considers solely interband scattering, and both bands can be modeled as symmetric (around the Fermi level) and flat, thus each band is…
We reformulate the Eliashberg's equation for the superconducting transition within the quasi-particle description, which takes account of the heavy electron mass. We discuss the superconductivity of CeIr_{x}Co_{1-x}In_5 by using such a…
The heat capacity anomaly at the transition to superconductivity of the layered superconductor MgB$_2$ is compared to first-principles calculations with the Coulomb repulsion, $\mu^\ast$, as the only parameter which is fixed to give the…
The two-band Hubbard model involving subbands of different widths is investigated via finite-temperature exact diagonalization (ED) and dynamical mean field theory (DMFT). In contrast to the quantum Monte Carlo (QMC) method which at low…
We present structural, electrical, and thermoelectric potential measurements on high-quality single crystals of ZrTe$_{1.8}$ grown from isothermal chemical vapor transport. These measurements show that the Te-deficient ZrTe$_{1.8}$, which…
We have measured details of the quasi one-dimensional Fermi-surface sections in the organic superconductor kappa-(BEDT-TTF)_2 Cu(NCS)_2 and its deuterated analogue using angle-dependent millimetre-wave techniques. There are significant…
We report on the interplay of localized and extended degrees of freedom in the metallic state of high-temperature superconductors in a multiband setting. Various ways in which the bare magnetic response may become incommensurate are…
We report magnetic field dependent magnetization and microwave impedance measurements on a MgB2 superconductor prepared by high pressure synthesis. We find that the upper critical field is linearly dependent on temperature near Tc and the…
Infrared optical investigations of $\alpha$-(BEDT-TTF)$_2$I$_3$ have been performed in the spectral range from 80 to 8000~cm$^{-1}$ down to temperatures as low as 10~K by applying hydrostatic pressure. In the metallic state, $T > 135$~K, we…
Here, we report the discovery of superconductivity in a new transition metal-chalcogenide compound, i.e. Nb2Pd0.81S5, with a transition temperature Tc > 6.6 K. Despite its relatively low Tc, it displays remarkably high and anisotropic…
We calculate the one-particle spectral functions above the superconducting transition temperature $T_{C}$, in the framework of a functional integral approach. The coupling of the electronic self-energy to pair fluctuations, which are…
We analyze the many-particle correlations that affect the optical properties of two-dimensional semiconductors. These correlations manifest themselves through the specific optical resonances such as excitons, trions, etc. Starting from the…
We have investigated the surface and bulk electronic structures of the superconducting type-II Dirac semimetal 1T-PdSeTe. The superconducting transition temperature $T_C = 3.2$ K was almost twice as high as $T_C = 1.6$ K in 1T-PdTe$_2$.…
Migdal-Eliashberg theory of boson-mediated superconductivity contains a $\sqrt{\lambda}$ divergence in the critical temperature $T_c$ for strong electron-boson coupling $\lambda$. In the conventional Migdal-Eliashberg theory, the…
In the 35 years since the discovery of cuprate superconductors, we have not yet reached a unified understanding of their properties, including their material dependence of the superconducting transition temperature $T_{\text{c}}$. The…
We report LDA calculated band structure, densities of states and Fermi surfaces for recently discovered Pt-pnictide superconductors APt3P (A=Ca,Sr,La), confirming their multiple band nature. Electronic structure is essentially three…
Pursuing higher-temperature superconductors under ambient pressure continues to be a prominent topic in materials discovery. Isomorphic structures like MgB2 exhibit potential for conventional BCS-type superconductivity, but their transition…
Previous theoretical studies on superconductivity were focused on the static states and adiabatic processes. Quantum mechanics simulations of time-dependent processes in superconductors were rarely performed previously. Here we use…
The low-temperature specific heat of a superconductor Mo3Sb7 with T_c = 2.25 (0.05) K has been measured in magnetic fields up to 5 T. In the normal state, the electronic specific heat coefficient gamma_n, and the Debye temperature Theta_D…