Related papers: Decrease of d-wave pairing strength in spite of th…

We report on semiclassical angle-dependent magnetoresistance oscillations (AMRO) and the Shubnikov-de Haas effect in the electron-overdoped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_4$. Our data provide convincing evidence for magnetic…

The dynamic spin susceptibility, $\chi''(\omega)$, has been measured over the energy range of $2 \leq \omega \leq 10$ meV for overdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$. Incommensurate (IC) spin excitations are observed at 8 K for all…

By using the determinant Quantum Monte Carlo method, the magnetic and pairing correlation of the Na$_{x}$CoO$_{2}\cdot$yH$_{2}$O system are studied within the Hubbard model on a bilayer triangular lattice. The temperature dependence of spin…

We study the doping evolution of spin excitations in a 1D Hubbard model and its downfolded spin Hamiltonians, by using exact diagonalization combined with cluster perturbation theory. In all models, we observe hardening (softening) of spin…

We report a study of magnetic, thermal, and transport properties of La(3+) substituted Sr2RuO4, performed in order to investigate the effects of additional electron doping in this correlated metal. A gradual enhancement of the electronic…

We provide an explanation of the spin-freezing transition recently observed by Chou et al. (Phys. Rev. Lett. 71, 2323 (1993)) in La_{2-x}Sr_x CuO_4 for x <= 0.02. We propose that topological excitations of the 2D Heisenberg quantum…

From measurements of the ^{63}Cu Knight shift (K) and the nuclear spin-lattice relaxation rate (1/T_{1}) under magnetic fields from zero up to 28 T in the slightly overdoped superconductor TlSr_{2}CaCu_{2}O_{6.8} (T_{c}=68 K), we find that…

The normal-state in-plane resistivity (\rho_{ab}) is measured in lightly Zn-doped La_{2-x}Sr_xCuO_4 (LSCO) crystals with 0.06 \leq x \leq 0.17 to systematically study the localization behavior. It is found that the localization temperature,…

The F doped LaFeAsO, a recently discovered superconductor with the high Tc of 26 K, has been studied by the resistivity, magnetic susceptibility, and heat capacity measurements in the F doping range from 0 to 0.14 (x in LaFeAsO1-xFx). In…

The effect of the the $c$ axis compression on the electronic structure and superconducting properties of the HTSC cuprate La$_{2-x}$Sr$_x$CuO$_4$ at different doping is investigated. The electronic structure of quasiparticle excitations is…

We demonstrate the presence of ferromagnetic (FM) fluctuations in the superconducting and non-superconducting heavily overdoped regimes of high-temperature superconducting copper oxides, using (Bi,Pb)_2_Sr_2_CuO_6+delta_ (Bi-2201) single…

Muon spin relaxation ($\mu$SR) measurements in high transverse magnetic fields ($\parallel \hat c$) revealed strong field-induced quasi-static magnetism in the underdoped and Eu doped (La,Sr)$_{2}$CuO$_{4}$ and…

The spectral-weight distribution in recent neutron scattering experiments on the parent compound La$_2$CuO$_4$ (LCO), which are limited in energy range to about 450\,meV, is studied in the framework of the Hubbard model on the square…

The spin dynamics of high temperature superconductors measured by inelastic neutron scattering is reviewed. The spin susceptibility evolves a lot with increasing doping from the undoped insulating state to the overdoped metallic state. In…

We have used inelastic neutron scattering to examine the magnetic fluctuations at intermediate frequencies in the simplest high temperature superconductor, La_{2-x}Sr_{x}Cu_{4}. The suppression of the low energy magnetic response in the…

Upon doping, Mott insulators often exhibit symmetry breaking where charge carriers and their spins organize into patterns known as stripes. For high-Tc superconducting cuprates, stripes are widely suspected to exist in a fluctuating form.…

A model of CuO$_2$ planes of cuprate perovskites, containing $d_{x^2-y^2}$ copper orbitals and symmetric combinations of oxygen $p_\sigma$ orbitals, is investigated using the strong coupling diagram technique. This approach allows one to…

The mechanism of high-Tc superconductivity is investigated with interests on the microscopic aspects of the condensation energy. The theoretical analysis is performed on the basis of the FLEX approximation which is a microscopic description…

We use high-resolution inelastic neutron scattering to study the low-temperature magnetic excitations of electron-doped superconducting Pr$_{0.88}$LaCe$_{0.12}$CuO$_{4-\delta}$ ($T_c=21\pm 1$ K) over a wide energy range (4…

Cold neutron triple-axis measurements have been used to investigate the nature of the long-wavelength spin dynamics in strongly-doped La$_{1-x}$Sr$_{x}$MnO$_3$ single crystals with $x$=0.2 and 0.3. Both systems behave like isotropic…