@@ -29,7 +29,7 @@ The roughness profile is described by a normally-distributed random function. Th
* The cross correlation length $\xi\_{\perp}$ is the vertical distance over which the correlation between layers is damped by a factor $1/e$. It is assumed to be the same for all interfaces. If $\xi\_{\perp} = 0$ there is no correlations between layers. If $\xi\_{\perp}$ is much larger than the layer thickness, the layers are perfectly correlated.
