  The ion-sputtering induced transient enhanced intermixing has been studied by
molecular dynamics (MD) simulations in Pt/Ti and its anomalous nature has been
explained as a superdiffusive transient enhanced interdiffusion. We find
ballistic mixing and a robust mass effect in Pt/Ti. The sum of the square of
atomic displacements ($<R^2>$) asymptotically grows nonlinearily and scales as
$N^2$ and $\sim t^2$, where $N$ and $t$ are the ion-number fluence and the time
of ion-sputtering, respectively. This anomalous behavior explains the high
diffusity tail in the concentration profile obtained by Auger electron
spectroscopy depth profiling (AES-DP) analysis in Pt/Ti/Si substrate (Pt/Ti)
multilayer. In Ta/Ti/Pt/Si multilayer we find a linear time scaling of $<R^2 >
\propto t$ at the Ti/Pt interface indicating the suppression of superdiffusive
features. We propose a qualitative explanation based on the accelerative effect
of nonlinear forces provbided by the anharmonic host lattice.
