Related papers: Fluctuation diamagnetism in high temperature super…
The temperature dependencies of the excess conductivity $\sigma'(T)$ and possible pseudogap (PG), in a Dy$_{0.6}$Y$_{0.4}$Rh$_{3.85}$Ru$_{0.15}$B$_4$ polycrystal were studied for the first time. It was shown that $\sigma'(T)$ near T$_{c}$…
We explore the role of phase fluctuations in a 3-dimensional s-wave superconductor, NbN, as we approach the critical disorder for the destruction of the superconducting state. Scanning tunneling spectroscopy measurements reveal that in the…
The magnetization of three high-quality single crystals of YBa$_{2}$Cu$_{3}$O$_{6+x}$, from slightly overdoped to heavily underdoped,has been measured using torque magnetometry. Striking effects in the angular dependence of the torque for…
The electronic structure in the normal state of CeFeAsO0.89F0.11 oxypnictide superconductors has been investigated with x-ray absorption and photoemission spectroscopy. All the data exhibit signatures of Fe d-electron itinerancy. Exchange…
We study the effect of fluctuations on the {\bf ac} conductivity of a layered superconductor both for $c$-axis and $ab$-plane electromagnetic wave polarizations. The fluctuation contributions of different physical nature and signs…
In highly anisotropic cuprate superconductors it is generally accepted that the reversible magnetization vector, M, is essentially perpendicular to the superconducting CuO2 layers in a wide range of crystal orientations with respect to the…
We present a theory of the interplane conductivity of bilayer high temperature superconductors, focusing on the effect of quantal and thermal fluctuations on the oscillator strengths of the superfluid stiffness and the bilayer plasmon. We…
It is very important to elucidate the mechanism of superconductivity for achieving room temperature superconductivity. This paper is a short review article on the mechanism of high-temperature superconductivity. In the first half of this…
We have measured magnetization at high pressure in the uranium ferromagnetic superconductor UGe$_2$ and analyzed the magnetic data using Takahashi's spin fluctuation theory. There is a peak in the pressure dependence of the width of the…
Thermal fluctuations of the order parameter in an ultrathin triangular shaped superconducting structure are studied near $T_{c}$, in zero applied field. We find that the order parameter is prone to much larger fluctuations in the corners of…
We consider an extended Hubbard model with nearest-neighbor correlated hopping and next nearest-neighbor hopping t' obtained as an effective model for cuprate superconductors. Using a generalized Hartree-Fock BCS approximation, we find that…
Motivated by recent experiments on isovalent-doped 1111 iron-based superconductors LaFeAs$_{1-{x}}$P$_{x}$O$_{1-{y}}$F$_{y}$ and the theoretical study that followed, we investigate, within the five orbital model, the correlation between the…
We describe the relation between spin fluctuations and superconductivity in a highly-ordered sample of YBaCu3O6.5 using both polarized and unpolarized neutron inelastic scattering. The spin susceptibility in the superconducting phase…
The pseudogap phenomena observed on cuprate high temperature superconductors are investigated based on the exact diagonalization method on the finite cluster t-J model. The results show the presence of the gap-like behavior in the…
The recently observed an intimate link between the nature of the strange metallic normal-state and superconductivity in the overdoped electron-doped cuprate superconductors is calling for an explanation. Here the intrinsic correlation…
The iron-based superconductor FeSe offers a unique possibility to study the interplay of superconductivity with purely nematic as well magnetic-nematic order by pressure (p) tuning. By measuring specific heat under p up to 2.36GPa, we study…
Using a dynamical cluster quantum Monte Carlo approximation, we investigate the effect of local disorder on the stability of d-wave superconductivity including the effect of electronic correlations in both particle-particle and…
We study the order parameter phase fluctuation effects in cuprate superconductors near T=0, using a quasi-two-dimensional d-wave BCS model. An effective phason theory is obtained which is used to estimate the strength of the fluctuations,…
From an analysis of the specific heat of one of the cuprate superconductors it is shown, that even if a large part of the experimental specific heat associated with the superconducting phase transition is due to fluctuations, this part must…
High temperature superconductivity encompasses the cuprates, nickelates, iron pnictides, and LaH$_x$ compounds. The first three groups of compounds involve in the pairing electrons, which are strongly to moderately correlated, whereas in…