  We present a stability analysis of a modified nonlinear Schroedinger equation
describing the propagation of ultra-short pulses in negative refractive index
media. Moreover, using methods of quantum statistics, we derive a kinetic
equation for the pulses, making it possible to analyze and describe partial
coherence in metamaterials. It is shown that a novel short pulse soliton, which
is found analytically, can propagate in the medium.
