Nyquist method for Wigner-Poisson quantum plasmas.
By means of the Nyquist method, we investigate the linear stability of electrostatic waves in homogeneous equilibria of quantum plasmas described by the Wigner-Poisson system. We show that, unlike the classical Vlasov-Poisson system, the Wigner-Poisson case does not necessarily possess a Penrose functional determining its linear stability properties. The Nyquist method is then applied to a two-stream distribution, for which we obtain an exact, necessary and sufficient condition for linear stability, as well as to a bump-in-tail equilibrium.
Haas
F
F
Laboratório Nacional de Computação Científica - LNCC, Avenue Getúlio Vargas, 333 25651-07 Petrópolis, Rio de Janeiro, Brazil. ferhaas@lncc.br
Manfredi
G
G
Goedert
J
J