Tunneling in chains of quantum dots

The definition of time-dependent overlap between Wannier functions is introduced to estimate electron mobility in a periodic lattice. Time evolution studies carried out in simple band models yield an easy analysis of the role of bandwidth and density-of-states on tunneling time. Comparison of tunneling times in one-dimensional superlattices built of both homogeneous semiconductor quantum dots and two-shell semiconductor antidot nanocrystals reveals that while a monotonic increasing in electron mobility vs nanocrystal density can be seen in the first case, a maximum in mobility is found in the second kind of superlattices for a critical value of the nanocrystal density.