Yuyao Zha | Searcharxiv

arXiv1995

Model of C-Axis Resistivity of High-$\Tc$ Cuprates

We propose a simple model which accounts for the major features and systematics of experiments on the $c$-axis resistivity, $ρ_c$, for $\lsco$, $\ybco$ and $\bsco $. We argue that the $c$-axis resistivity can be separated into contributions from in-plane dephasing and the $c$-axis ``barrier'' scattering processes, with the low temperature semiconductor-like behavior of $ρ_c$ arising from the suppression of the in-plane density of states measured by in-plane magnetic Knight shift experiments. We report on predictions for $ρ_c$ in impurity-doped $\ybco$ materials.

cond-mat↗

arXiv1995

Neutron Scattering and $d$-Wave Symmetry in the Cuprates

In this comment we demonstrate that the general conjectures of Fong $et~ al$ on their ${\rm YBa_2Cu_3O_7}$ neutron experiments are realized in concrete calculations of the neutron scattering structure factor $S({\bf q} , ω)$ in this material. We make predictions for similar experiments in ${\rm La_2Sr_{0.15}Cu_{1.85}O_4}$, which yield a different q-structure due to the different fermiology. Our calculations address both the frequency and wave-vector dependence of the data and (1) include realistic Fermi surface effects (2) are compatible with the normal state data and (3) demonstrate the consistency of a $d$-wave order parameter, in ${\rm YBa_2Cu_3O_7}$ although they appear to be also compatible with an alternate symmetry specific to the orthorhombic bi-layer system.

cond-mat↗