  The classical walking behaviors of a single atom in an amplitude-modulated
standing wave lattice beyond the internal dynamics are investigated. Based on a
simple effective model, we identify a diversity of dynamic regimes of atomic
motion by periodically adjusting the lattice depth. Harmonic oscillation or
pendulum rotation with classical step-jumping, random scattering walking,
chaotic transportation, quasi-periodic trapped motion and roughly ballistic
free flying are found in this simple model within different parametric regions
by approximate analyses. Our study demonstrates a complex motion of single atom
in modulating optical lattice beyond the quantum description.
