Related papers: The Manganites as Metallic Semiconductors
The Monte Carlo Ferromagnetic Ising model was used to study the electrical properties of manganese oxides due to the charge ordering phase occurring at doping, x = 0.5. The half-doped manganites have an insulator antiferromagnetic ground…
The physics of the ferromagnetic phase of the ``double exchange'' model has been widely discussed in the context of the CMR manganites. Usually, the double exchange ferromagnet is treated is classically, by mapping it onto an effective…
The phenomenology of iron-pnictides superconductors can be explained in the framework of a three bands s\pm wave Eliashberg theory with only two free parameters plus a feedback effect i.e. the effect of the condensate on the…
The main properties of magnetized strangelets, namely, their energy per baryon, radius and electric charge, are studied. Temperature effects are also taken into account in order to study their stability compared to the 56Fe isotope and…
ZrTe$_5$ is considered a potential candidate for either a Dirac semimetal or a topological insulator in close proximity to a topological phase transition. Recent optical conductivity results motivated a two-band model with a conical…
The two-band model as introduced by Suhl, Matthias and Walker [Phys. Rev. Lett. 3, 551 (1959)] accounts for multiple energy bands in the vicinity of the Fermi energy which could contribute to electron pairing in superconducting systems.…
We show that two tight binding electrons that repel may form a bounded pair in two dimensions. The paired states form a band with energies that scale like the strength of the interaction potential. By applying an electric field we show that…
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 Tc oxides, pnictides and heavy fermions. In this work we study a…
A version of the magnetoimpurity theory of the colossal magnetoresistance materials suitable for the double exchange ferromagnetic nondegenerate semiconductors is presented. It provides an explanation of the nonmonotonic temperature…
Magnons in antiferromagnetic insulators couple strongly to conduction electrons in adjacent metals. We show that this interfacial tie can lead to superconductivity in a tri-layer consisting of a metal sandwiched between two…
This article is a review o over theory of superconductivity, which is constructed for systems with two overlapping energy bands at the Fermi surface and with arbitrary charge carrier density.There is taken into account all possible kinds of…
In a superconductor electrons form pairs and electric transport becomes dissipation-less at low temperatures. Recently discovered iron based superconductors have the highest superconducting transition temperature next to copper oxides. In…
The best thermoelectric materials are believed to be heavily doped semiconductors. The presence of a bandgap is assumed to be essential to achieve large thermoelectric power factor and figure of merit. In this work, we study HgTe as an…
Critical phenomena of ferromagnetic transition in colossal magnetoresistance manganites are theoretically studied. Concerning the critical exponents for this transition, there still remains controversy among experimental results. In order…
We construct a multi-band Hubbard model on the lattice obtained by "decorating" a closely packed $d$-dimensional lattice $\mathcal{M}$ (such as the triangular lattice) where $d\ge2$. We take the limits in which the Coulomb interaction and…
Polycrystalline samples of the recently discovered MgCNi3 superconductor were investigated by transport, ac susceptibility, dc magnetization and specific heat measurements in magnetic fields up to 16 T. Consistent results were obtained for…
MgB_2 is considered as a binary system with 2D electrons. The classic BCS theory is applied to this system. The transition temperature is found to be relatively high, because 2D electrons are more capable of moving with the atoms, on top of…
The spin-wave spectrum in the metallic ferromagnetic lantha-num cubic manganites was investigated. The interactions with four coordination spheres (32 neighbors) were taken into ac-count. The Heisenberg superexchange between all manganese…
We study a model of mesoscale superconducting puddles in a metal, represented as dynamical impurities interacting with a finite number of electronic channels via Andreev and normal scattering. We identify conditions under which the…
The electrical resistivity of liquid hydrogen has been measured at the high dynamic pressures, densities and temperatures that can be achieved with a reverberating shock wave. The resulting data are most naturally interpreted in terms of a…