Related papers: On possible superconductivity in the doped ladder …

The recently-discovered ``ladder'' compound LaCuO$_{2.5}$ has been found to admit hole doping without altering its structure of coupled copper oxide ladders. While susceptibility measurements on the parent compound suggest a spin gap and a…

Within the t-J ladder model, superconductivity with a modified d-wave symmetry in doped two-leg ladder cuprates is investigated based on the kinetic energy driven superconducting mechanism. It is shown that the spin-liquid ground-state at…

We present the results of a new Hubbard model for optimally doped LaSrCuO. This model uses parameters derived from BLYP calculations on the cluster CuO6. It explicitly includes the Cu dx2-y2 and dz2 orbitals, the O psigma orbitals, and the…

Recently, Matsukawa et al. have discovered a new superconductor Pr_2Ba_4Cu_7O_15-delta in which metallic CuO double chains are responsible for the superconductivity. To investigate the superconductivity, we employ the d-p double chain model…

The interpretation of how superconductivity disappears in cuprates at large hole doping has been controversial. To address this issue, we present an experimental study of single-crystal and thin film samples of La$_{2-x}$Sr$_x$CuO$_4$…

The mechanism of superconductivity in Pr$_2$Ba$_4$Cu$_7$O$_{15-\delta}$ is studied using a quasi-one dimensional double chain model with appopriate hopping integrals, on-site $U$, and off-site repulsion $V_1$. Applying the fluctuation…

Recently, conductivity measurements were performed on the hole-doped two-leg ladder material Sr_{14-x}Ca_xCu_{24}O_{41}. In this work, we calculate the conductivity for doped two-leg ladders using a model of hole-pairs forming a strongly…

We present a single crystal Cu NMR study of the cuprate superconductor La$_{2-x}$Sr$_{x}$CuO$_4$ with hole doping levels between $x=2$\% and $8$\%. Measurements with short spin echo times enable us to systematically study the local…

Chemical doping has recently become a very important strategy to induce superconductivity especially in complex compounds. Distinguished examples include Ba-doped La$_2$CuO$_4$ (the first high temperature superconductor), K-doped BaBiO$_3$,…

The theoretical approach proposed recently for description of redistribution of electronic charge in multilayered selectively doped systems is modified for a system with finite number of layers. A special attention is payed to the case of a…

Pressure-induced superconductivity in a spin-ladder cuprate Sr$_2$Ca$_{12}$Cu$_{24}$O$_{41}$ has not been studied on a microscopic level so far although the superconductivity was already discovered in 1996. We have improved high-pressure…

By using solid state reaction method we have fabricated the hole doped $La_{1-x}Sr_xFeAsO$ superconductors with Sr content up to 0.13. It is found that the sharp anomaly at about 150 K and the low temperature upturn of resistivity are…

Discovery of new high TC superconductors, with TC > 23 K, continues to be challenging. We have doubled the existing TC of single crystal Sr3Ca11Cu24O41, a spin ladder cuprate, from 12K to 24K, using a gentle uniaxial pressure ~ 0.06 GPa. In…

We analyze the hole doping mechanism in Bi_2Sr_{2-x}La_xCuO_{6+\delta} (BSLCO). The singular optimum around x=0.35 is found to be connected with a feedback between the doped CuO_2 layers and its dopant reactant [La^{3+}/Bi^{3+}-O_\delta]…

We constructed an effective tight-binding model with five Cr $3d$ orbitals for LaOCrAs according to first-principles calculations. Basing on this model, we investigated possible superconductivity induced by correlations in doped LaOCrAs…

The techniques of growing films with different parameters in single process make it possible to build up a sample library promptly. In this work, with a precisely controlled moving mask, we synthetized superconducting…

By measuring the superconducting diamagnetic moments for an underdoped and an overdoped La_{2-x}Sr_xCuO_4 single crystal with equal qualities and roughly equal transition temperatures, it is found that the underdoped sample has only one…

Potassium-doped terphenyl has recently attracted attention as a potential host for high-transition-temperature superconductivity. Here, we elucidate the many-body electronic structure of recently synthesized potassium-doped terphenyl…

We propose a model for high-Tc superconductors that includes both the spin fluctuations of the Cu++ magnetic ions and of the spins of O-- doped holes (spinons). The charge of the dopants (holons) is associated to quantum skyrmion…

We study signatures of superconductivity in a 2--leg "checkerboard" Hubbard ladder model, defined as a one--dimensional (period 2) array of square plaquettes with an intra-plaquette hopping $t$ and inter-plaquette hopping $t'$, using the…