Itinerant effects and enhanced magnetic interactions in Bi-based multilayer cuprates

Superconducting order parameter symmetry in multilayer cuprates.

In this paper we classify the allowed order parameter symmetries in multilayer cuprates and discuss their physical consequences, with emphasis on Josephson tunneling and impurity scattering. Our solutions to the gap equation are based on highly non-specific forms for the interand intra-plane pairing interactions in order to arrive at the most general conclusions. Within this framework, the bi-l...

Magnetically Coupled Bi-layer Cuprates

We propose a possible mechanism of pseudo spin gap anomaly(PSGA) in magnetically coupled bi-layer cuprates without any fermion pairing instability. In our proposal PSGA does not necessarily require the spin-charge separation or the breakdown of the Fermi liquid description of a normal state of the cuprate superconductor. The low energy magnetic excitations are mainly governed by the itinerant n...

Scaling properties of the optical conductivity of Bi-based cuprates

We present novel infrared optical conductivity data on the three layer high Tc superconductor Bi2Sr2Ca2Cu3O10 at optimal doping. We extend the analysis of an earlier publication, providing a universal scaling function σ(ω, T ) = T−1g(ω/T ) for the optical conductivity. In the present manuscript we obtain a good scaling collapse of the experimental curves on the g(ω/T ) over a wide range of valu...

Magnetic anisotropy in itinerant magnets

Doping evolution of itinerant magnetic excitations in Fe-based oxypnictides

Employing the four-band tight-binding model we study theoretically the doping dependence of the spin response in the normal state of novel Fe-based pnictide superconductors. We show that the commensurate spin density wave (SDW) transition that arises due to interband scattering between the hole α-pockets and the electron β-pockets disappears already at the doping concentration x ≈ 0.04 reflecti...