相关论文: Superconductivity and magnetic fluctuations in ele…
The quantum spin fluctuations of the S = 1/2 Cu ions are important in determining the physical properties of the high-transition temperature (high-Tc) copper oxide superconductors, but their possible role in the electron pairing for…
Within the kinetic energy driven superconducting mechanism, the magnetic nature of cuprate superconductors is discussed. It is shown that the superconducting state is controlled by both charge carrier gap function and quasiparticle coherent…
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 present a high-pressure NMR study of the overdoped iron pnictide superconductor NaFe$_{0.94}$Co$_{0.06}$As. The low-energy antiferromagnetic spin fluctuations in the normal state, manifest as the Curie-Weiss upturn in the spin-lattice…
Superconductivity appears to compete against the spin-density-wave in Fe pnictides. However, optimally cobalt doped samples show a quasi-two-dimensional spin excitation centered at the (0.5, 0.5, L) wavevector, "the spin resonance peak",…
A comprehensive inelastic neutron scattering study of magnetic excitations in the near-optimally doped high-temperature superconductor ${\rm YBa_{2}Cu_{3}O_{6.85}}$ is presented. The spin correlations in the normal state are commensurate…
Co nuclear-quadrupole-resonance (NQR) measurements were performed on various bilayered hydrate cobaltate Na_x(H_3O)_zCoO_2\cdot yH_2O with different values of the superconducting and magnetic-ordering temperatures, T_c and T_M,…
It is a distinct possibility that spin fluctuations are the pairing interactions in a wide range of unconventional superconductors. In the case of the high-transition-temperature (high-$T_c$) cuprates, in which superconductivity emerges…
We study the emergence of a magnetic resonance in the superconducting state of the electron-doped cuprate superconductors. We show that the recently observed resonance peak in the electron-doped superconductor…
We use inelastic neutron scattering to probe magnetic excitations of an optimally electron-doped superconductor Nd$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ above and below its superconducting transition temperature $T_c=25$ K. In addition to…
Correlation effects in CuO$_2$ layers give rise to a complicated landscape of collective excitations in high-T$_{\rm c}$ cuprates. Their description requires an accurate account for electronic fluctuations at a very broad energy range and…
A neutron scattering study of heavily hole-overdoped superconducting KFe$_2$As$_2$ revealed a well-defined low-energy incommensurate spin fluctuation at [$\pi(1\pm2\delta$),0] with $\delta$ = 0.16. The incommensurate structure differs from…
We present a systematic study of spin dynamics in a superconducting ground state, which itself is a doped-Mott-insulator and can correctly reduce to an antiferromagnetic (AF) state at half-filling with an AF long-range order (AFLRO). Such a…
Extending our previous studies we present results for the doping-, momentum-, frequency-, and temperature- dependence of the kink-like change of the quasiparticle velocity resulting from the coupling to spin fluctuations. In the nodal…
Polarized and unpolarized neutron triple-axis spectrometry was used to study the dynamical magnetic susceptibility $\chi^{\prime\prime}({\bf q},\omega)$ as a function of energy ($\hbar\omega$) and wave vector (${\bf q}$) in a wide…
We report ^{59}Co NMR studies in single crystals of cobalt oxide superconductor Na_{0.42}CoO_{2}\cdot1.3H_{2}O (T_c=4.25K) and its parent compound Na_{0.42}CoO_{2}. We find that both the magnitude and the temperature (T) dependence of the…
The antiferromagnetic correlation plays an important role in high-T$_{c}$ superconductors. Considering this effect, the magnetic excitations in n-type cuprates near the optimal doping are studied within the spin density wave description.…
Superconductivity in copper oxides emerges on doping holes or electrons into their Mott insulating parent compounds. The spin excitations are thought to be the mediating glue for the pairing in superconductivity. Here the momentum and…
As a hallmark of electronic correlation, spin-charge interplay underlies many emergent phenomena in doped Mott insulators, such as high-temperature superconductivity, whereas the half-filled parent state is usually electronically frozen…
We systematically analyze the influence of the superconducting gap symmetry and the electronic structure on the dynamical spin susceptibility in superconducting Na_xCoO_2$\cdot y$H_2O within a three different models: the single a_{1g}-band…