  Due to the mechanism of confinement, as known from quantum chromodynamics, it
is difficult to observe individual particles carrying fractional quantum number
(e.g. quark with fractional electric charge). A condensed matter example of
fractionalized particles is spinons in quasi-one-dimensional spin systems,
which are domain walls in the background of Neel configurations carrying
spin-1/2. Using the time-evolving block decimation algorithm, we visualize the
nontrivial domain wall dynamics induced by the confine mechanism in a two-leg
spin-1/2 ladder. It can be illustrated by a simple single-particle picture of
Bloch oscillation, not only qualitatively but also quantitatively. We propose
the experimental realization and the real time detection of the domain wall
dynamics in the ultra-cold boson systems of $^{87}$Rb.
