Hi everyone, I have been reading a recent Nature paper (Stengel and Spaldin, 2006) where ab initio simulations on SrRuO_3/SrTiO_3/SrRu_O3 nanocapacitors have been performed to investigate the origin of the so-called dead layer effect in thin-film nanocapacitors. They arrive at several interesting results which i will try to summarise 1) SrRuO_3 electrodes were found to have poor electron screening which resulted in high charge penetration inside the electrodes. This also resulted in a large depolarization field inside the SrTiO_3 dielectric layer which resulted in the observed capacitance being around 6 times lesser than the expected capacitance 2) The results also show that at the interface of the metal and the dielectric, the dielectric constant is continuos. Specifically, for the metal the dielectric constant is the same as that for the dielectric at the interface and increases to infinity at a large enough distance from the dielectric. My question is, is the continuity in dielectric constant anything special? Will all physical properties be continuos at the interface? Also, is there any way i can model the spatial behavior of the dielectric constant of the metal?