Conductivity sum rule, implication for in-plane dynamics and c-axis response

Abstract

Recently observed $c$-axis optical sum rule violations indicate non-Fermi liquid in-plane behavior. For coherent $c$-axis coupling, the observed flat, nearly frequency independent $c$-axis conductivity ${\sigma }_1(\omega )$ implies a large in-plane scattering rate $\Gamma$ around $(0,\pi )$ and therefore any pseudogap that might form at low frequency in the normal state will be smeared. On the other hand incoherent $c$-axis coupling places no restriction on the value of $\Gamma$ and gives a more consistent picture of the observed sum rule violation which, we find in some cases, can be less than half.

3 figures. To appear in PRB

References in corpus (2)

• The pseudogap in high-temperature superconductors: an experimental survey
• Interlayer Conductivity in the Superconductor Tl-Ba-Cu-O: Energetics and Energy Scales

Cited by in corpus (4)

• Comparison of in- and out-of-plane charge dynamics in YBa_2Cu_3O_{6.95}
• Interlayer coupling and the c-axis quasiparticle transport in high-$T_c$ cuprates
• C-axis Optical Sum Rule in Josephson Coupled Vortex State
• Effects of an in-plane magnetic field on c-axis sum rule and superfluid density in high-$T_c$ cuprates