COMPETING INTERACTIONS AND QUANTUM NONSPREADING WAVE-PACKETS

We study the evolution of a single mode of the quantized electromagnet ic field interacting with both a collection of resonant two-level atom s and a Kerr medium. Each of these interactions separately leads to a spreading of the initial field coherent states. Acting simultaneously, these two mechanisms of dispersion can cancel each other for special initial atomic states, allowing the propagation of field wave packets without spreading in the quantum phase space.