Related papers: Optical Conductivity in a Two-Band Superconductor:…

CaBi$_2$ is a recently discovered type-I superconductor with $T_c=2$~K and a layered crystal structure. In this work electronic structure, lattice dynamics and electron-phonon interaction are studied, with a special attention paid to the…

Two-dimensional semiconductor-superconductor heterostructures form the foundation of numerous nanoscale physical systems. However, measuring the properties of such heterostructures, and characterizing the semiconductor in-situ is…

To understand superconductivity in Chevrel phase compounds and guide the search for interesting properties in materials created with Chevrel phase molecules as building blocks, we use ab-initio methods to study the properties of single…

To understand the superconductivity in MgB2, several two-band models of superconductivity were proposed. In this paper, by using the relativistic fermion model, we clearize the effect of the lower band in the superconductivity.

We address how the finite frequency real conductivity $\sigma(\omega)$ in the underdoped cuprates is affected by the pseudogap, contrasting the behavior above and below $T_c$. The f-sum rule is analytically shown to hold. Here we presume…

First-principles studies of the electron-phonon coupling in graphene predict a high coupling strength for the $\sigma$ band with $\lambda$ values of up to 0.9. Near the top of the $\sigma$ band, $\lambda$ is found to be $\approx 0.7$. This…

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…

The optical properties of the superconducting single crystal Rb$_{0.8}$Fe$_{1.68}$Se$_2$ with $T_{c}$ $\simeq$ 31 K have been measured over a wide frequency range in the $ab$ plane. We found that the optical conductivity is dominated by a…

We performed de Haas-van Alphen (dHvA) oscillation measurements and band-structure calculations for YNi$_2$B$_2$C. Our improved band structure successfully explained the origins of the large dHvA frequencies $\beta$ and $\zeta$, which were…

We present a systematic angle-resolved photoemission spectroscopic study of the high-Tc superconductor class (Sr/Ba){1-x}(K/Na)xFe2As2. By utilizing a photon-energy-modulation contrast and scattering geometry we report the Fermi surface and…

Motivated by recent optical measurements on a number of strongly correlated electron systems, we revisit the dependence of the conductivity of a Fermi liquid, \sigma(\Omega,T), on the frequency \Omega and temperature T. Using the Kubo…

We report results for the superconducting transition temperature and anisotropic energy gap for pure Niobium based on Eliashberg's equations and electron and phonon band structures computed from density functional theory. The electronic…

Strong electron interactions in solids increase effective mass, and shrink the electronic bands [1]. One of the most unique and robust experimental facts about iron-based superconductors [2-4] is the renormalization of the conduction band…

Superconductivity is observed with critical temperature $T_{c}$ = 2.0 K in self-flux-grown single crystals of $CaBi_{2}$. This material adopts the $ZrSi_{2}$ structure type with lattice parameters a = 4.696(1) $\AA$, b = 7.081(2) $\AA$ and…

We report the electronic structure and related properties of the superconductor Ta2PdSe5 as determined from density functional calculations. The Fermi surface has two disconnected sheets, both derived from bands of primarily chalcogenide p…

In strong-coupling superconductors with a short electron mean free path the self-energy effects in the superconducting order parameter play a major role in the phonon manifestation of the point-contact spectra at above-gap energies. We…

Pd$_3$Bi$_2$Se$_2$ is a rare realization of a superconducting metal with a non-zero $Z_2$ topological invariant. We report the growth of high-quality single crystals of layered Pd$_3$Bi$_2$Se$_2$ with a superconducting transition at $T_c$ ~…

The band structure and the Fermi surface of hexagonal diborides ZrB2, VB2, NbB2, TaB2 have been studied by the self-consistent full-potential LMTO method and compared with those for the isostructural superconductor MgB2. Factors responsible…

Ag$_5$Pb$_2$O$_6$ has attracted considerable attention due to its novel nearly-free-electron superconductivity, but its electronic structure and orbital character of the Cooper-pair electrons remain controversial. Here, we present a method…

For the first time, basing both on experimental facts and our theoretical consideration, we show that Fermi systems with flat bands should be tuned with the superconducting state. Experimental measurements on magic-angle twisted bilayer…