We describe a method allowing transient suppression of decoherence effects on
the atom-optics realization of the kicked rotor. The system is prepared in an
initial state with a momentum distribution concentrated in an interval much
sharper than the Brillouin zone; the measure of the momentum distribution is
restricted to this interval of quasimomenta: As most of the atoms undergoing
decoherence processes fall outside this detection range and thus are not
detected, the measured signal is effectively decoherence-free.Comment: 5 pages, 4 figures, revtex 4, submitted to PR
