Related papers: Multiband model of high Tc superconductors

With high-Tc cuprates in mind, properties of correlated dx2-y2-wave superconducting (SC) and antiferromagnetic (AF) states are studied for the Hubbard (t-t'-U) model on square lattices, using a variational Monte Carlo method. We employ…

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.…

The study of multi-band superconductivity is relevant for a variety of systems, from ultra cold atoms with population imbalance to particle physics, and condensed matter. As a consequence, this problem has been widely investigated bringing…

In this paper, a comprehensive study of the effects of Ni-doping on structural, electrical, thermal and magnetic properties of the NbB2 is presented. Low amounts (\leq 10 %) of Ni substitution on Nb sites cause structural distortions and…

We show that in a superconductor where two or more bands cross the Fermi level it is possible, in the framework of the conventional (s-wave) BCS theory, that the sign of the superconducting gap is different on the different sheets of the…

The electronic band structures of the new superconducting (with T_c up to 7.7K) ternary silicides M(A_{0.5}Si_{0.5})_2 (M= Ca, Sr, Ba; A= Al, Ga) in the AlB_2-type structure have been investigated using the full-potential LMTO method. The…

Numerical evidence for superconductivity in the single-band Hubbard model is elusive or ambiguous despite extensive study, raising the question of whether the single-band Hubbard model is a faithful low energy effective model for cuprates,…

Motivated by the discovery of superconductivity in boron-doped (B-doped) diamond, we investigate the localization and superconductivity in heavily doped semiconductors. The competition between Anderson localization and s-wave…

We have analyzed the $B_{1g}$ and $B_{2g}$ Raman spectra of electron-doped cuprate superconductors Nd$_{2-x}$Ce$_{x}$CuO$_4$ and Pr$_{2-x}$Ce$_{x}$CuO$_4$ using a weakly coupled two-band model. One of these two bands is centered around…

Traditionally one and two-point correlation functions are used to characterize many-body systems. In strongly correlated quantum materials, such as the doped 2D Fermi-Hubbard system, these may no longer be sufficient because higher-order…

The multielectron LDA+GTB approach has been developed to calculate electronic structure of strongly correlated cuprates. At low energies the effective Hamiltonian of the $t - t' - t" - {t_ \bot } - {J^ * } - {J_ \bot }$-model has been…

The doping dependent isotope effect on the critical temperature (Tc) is calculated for multi-band multi-condensate superconductivity near a 2.5 Lifshitz transition. We focus on multi-band effects that arises in nano-structures and in…

ARPES studies have established that the high-$T_c$ cuprates with single and double CuO$_2$ layers evolve from the Mott insulator to the pseudogap state with a Fermi arc, on which the superconducting (SC) gap opens. In four- to six-layer…

One path to high-temperature cuprate superconductors is doping a Mott insulator. In this paper, we study this system from the view point of higher-form symmetries. On the introduction of slave bosons, the $t-J$ model at a finite hole doping…

The discovery of high-$T_c$ superconductivity in the pnictides, materials with a Fermi surface determined by several bands, highlights the need to understand how superconductivity arises in multiband systems. In this effort, using symmetry…

We construct the holographic model of an $S^\pm$ multiband superconductor. This system is a candidate to explain the anomalous features of the iron-based superconductors (e.g. LaFeAsO, BFe2As2, and other pnictides and arsenides). We study…

The three band structure of the extended Emery model for the copper-oxide layered materials is analyzed for all the values of the effective tight-binding parameters. The model is characterized by the Cu-O site energy splitting, the Cu-O…

We study the distribution of electronic spectral weight in a doped antiferromagnet with various types of charge order and compare to angle resolved photoemission experiments on lightly doped La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) and electron doped…

We study the electronic instabilities of newly predicted Ni-based high-$T_c$ superconducting material La$_2$Ni$_2$Se$_2$O$_3$ based on the random phase approximation. Our calculations on the susceptibility indicate that the collinear…

All previous cuprate superconductors display a set of common features: (i) vicinity to a Cu 3$d^{9}$ configuration; (ii) separated CuO$_2$ planes; (iii) superconductivity for doping $\delta \sim$ 0.1$-$0.3. Recently [PNAS {\bf 24}, 12156…