Physical Review Letters
Conductivity between Luttinger Liquids in the Confinement Regime and c -Axis Conductivity in the Cuprate Superconductors
David G. Clarke, Steven P. Strong, P. W. Anderson
Abstract
We calculate the interliquid conductivity for Luttinger liquids, within the so-called ``confinement'' regime where interliquid hopping is completely incoherent. We argue that the interliquid conductivity behaves as ${\ensuremath{\sigma}}_{\ensuremath{\perp}}(\ensuremath{\omega})\ensuremath{\sim}{\ensuremath{\omega}}^{4\ensuremath{\alpha}}$, where $\ensuremath{\alpha}$ is the Luttinger liquid exponent. We discuss the effect of finite temperature, which is found to introduce a coherent weight into the conductivity. These results are in good agreement with experimental measurements of the frequency dependent normal state $c$-axis conductivity in the high-temperature superconductors YB${\mathrm{a}}_{2}$C${\mathrm{u}}_{3}$O ${}_{7\ensuremath{-}\ensuremath{\delta}}$ and La ${}_{2\ensuremath{-}x}$Sr ${}_{x}$Cu${\mathrm{O}}_{4}$.