Related papers: Superconductivity in a magnetically ordered backgr…
Effect of geometry on the superconductivity is considered. It is shown that the for nearly two dimensional BCS systems the critical temperature is rapidly increased with decreasing the thickness of the layer. The result is expected to be…
We give a brief review of superconductivity at ambient pressure in elements, alloys, and simple three-dimensional compounds. Historically these were the first superconducting materials studied, and based on the experimental knowledge gained…
In this paper we have studied the effect of external magnetic field in the co-existing phase of superconducting and anti-ferromagnetism of rare earth nickel borocarbides. The anti-ferromagnetism in these systems might have originated due to…
An array of one-dimensional conductors coupled by transverse hopping and interaction is studied with the help of a variational wave function. This wave function is devised as to account for one-dimensional correlation effects. We show that…
Attempts to explain correlated-electron superconductivity have largely focused on the proximity of the superconducting state to antiferromagnetism. Yet, there exist many correlated-electron systems that exhibit insulator-superconducting…
Superconducting bulk properties of ternary Nb2 BN are confirmed and are described by means of magnetization, electronic transport and specific-heat measurements. BCS conventional super- conductivity is found with Tc = 4.4 K. Critical fields…
It is shown that the superconducting intermetallic compound MgB2 possesses a narrow, partly filled "superconducting band" with Wannier functions of special symmetry in its band structure. This result corroborates previous observations about…
The recent discovery and subsequent developments of FeAs-based superconductors have presented novel challenges and opportunities in the quest for superconducting mechanisms in correlated-electron systems. Central issues of ongoing studies…
We present here an overview of thermal conductivity behavior in magnetic superconductors: rare-earth nickel borocarbide intermetallic compounds, RNi_{2}B_{2}C, and the 2122 rare-earth rutheno-cuprates. The borocarbide family of…
Superconductivity in strongly correlated systems is a remarkable phenomenon that attracts a huge interest. The study of this problem is relevant for materials as the high $T_c$ oxides, pnictides and heavy fermions. These systems also have…
Several experimental studies have shown the presence of spatially inhomogeneous phase coexistence of superconducting and non superconducting domains in low dimensional organic superconductors. The superconducting properties of these systems…
We consider local magnetic moments coupled to conduction electrons with on-site attraction, in order to discuss the interplay between pairing and magnetic order. We probe the ground state properties of this model on a one-dimensional…
The symmetry of superconductivity in borocarbides LuNi2B2C and YNi2B2C is an outstanding issue. Here an anisotropic s- wave order parameter (or s+g model) is proposed for these borocarbides. In spite of the dominant s- wave component the…
Exploration of superconductivity in light element compounds has drawn considerable attention because those materials can easily realize the high $T_{c}$ superconductivity, such as ${\mathrm{LnNi}}_{2}{\mathrm{B}_{2}}{\mathrm{C}}$ ($T_{c}$…
The (mean field based) BCS theory is considered one of the most successful theories in condensed matter physics. It is justified in ordinary metal superconductors the coherence length $\xi$ is large, with two important features: the order…
The properties of the known superconductors can be explained with the correlations dominated superconducting mechanism (CSM). The correlations have the spin correlation, the charge correlation and the spin-charge correlation, and their…
LaCo2B2 with a ThCr2Si2-type structure composed of alternately stacked La and CoB layers exhibits metallic electrical conductivity and Pauli paramagnetic behavior down to 2K. Bulk superconductivity with a Tc of ~4K emerges upon substitution…
We combine the BCS self-consistency condition, a semiclassical expansion for the spectral density and interaction matrix elements to describe analytically how the superconducting gap depends on the size and shape of a 2d and 3d…
We synthesized Nax(H3O)zCoO2yH2O samples with various Na/H3O ratios but with the constant Co valence of s = +3.40, and measured their magnetic properties to draw phase diagrams of the system. The superconductivity is very sensitive to the…
Superconductivity was recently reported in several quasicrystalline systems. These are materials which are structurally ordered, but since they are not translationally invariant, the usual BCS theory does not apply. At the present time, the…