Abstract:
Tunneling problems are characterized by different quantum time scales of motion. In this paper, we identify
a tunneling time scale, which is based on a simple variational principle. The method utilizes the stationary
eigenfunctions for a given one-dimensional potential structure, and it provides a truly local definition of the
tunneling time, independent of the asymptotic shape of the potential. We express the minimum tunneling time
in terms of the more common time scales obtained from the Larmor clock setup. Asymptotic formulas for both
the extreme quantum and the semiclassical limit are presented. As an experimental verification of the variational
approach we demonstrate that the minimum tunneling time governs the time a particle requires to
traverse the barrier in a symmetric double-well structure.
