Damping mechanism for the strongly renormalized $c$-axis charge transport in high-$T_c$ cuprate superconductors

Jae H. Kim, H. S. Somal, D. van der Marel

We analyze the $c$-axis infrared reflectivity of La${}_{1.85}$Sr${}_{0.15}$CuO${}_4$ single crystals. The plasma edge near 6 meV, observed below $T_c$, is due to Cooper-pair tunneling. T…