The classical and quantum dynamics of a particle trapped in a one-dimensional
infinite square well with a time periodic pulsed field is investigated. This is
a two-parameter non-KAM generalization of the kicked rotor, which can be seen
as the standard map of particles subjected to both smooth and hard potentials.
The virtue of the generalization lies in the introduction of an extra parameter
R which is the ratio of two length scales, namely the well width and the field
wavelength. If R is a non-integer the dynamics is discontinuous and non-KAM. We
have explored the role of R in controlling the localization properties of the
eigenstates. In particular the connection between classical diffusion and
localization is found to generalize reasonably well. In unbounded chaotic
systems such as these, while the nearest neighbour spacing distribution of the
eigenvalues is less sensitive to the nature of the classical dynamics, the
distribution of participation ratios of the eigenstates proves to be a
sensitive measure; in the chaotic regimes the latter being lognormal. We find
that the tails of the well converged localized states are exponentially
localized despite the discontinuous dynamics while the bulk part shows
fluctuations that tend to be closer to Random Matrix Theory predictions. Time
evolving states show considerable R dependence and tuning R to enhance
classical diffusion can lead to significantly larger quantum diffusion for the
same field strengths, an effect that is potentially observable in present day
experiments.Comment: 29 pages (including 14 figures). Better quality of Figs. 1,3 & 9 can
be obtained from author