Classical and quantum kinetics of the Zakharov system

A kinetic theory for quantum Langmuir waves interacting nonlinearly with quantum ion-acoustic waves is derived. The formulation allows for a statistical analysis of the quantum correction to the Zakharov system. The influence of a background random phase on the modulational instability is given. In the coherent case, the effect of the quantum correction is to reduce the growth rate. Moreover, in the classical limit, a bifurcation develops in the dispersion curves due to the presence of partial coherence. However, the combined effect of partial coherence and a quantum correction may give rise to an increased modulational instability growth rate, as compared to the classical case. The results may be of significance in dense astrophysical plasmas and laboratory laser-plasma systems. (c) 2005 American Institute of Physics.