Amplitude modulation of electron plasma oscillations in a dense electron-hole plasma

By using a quantum hydrodynamic model, the amplitude modulation of electron plasma oscillations (EPOs) in an unmagnetized dense electron-hole (e-h) quantum plasma is investigated. The standard reductive perturbation technique is used to derive one-dimensional nonlinear Schrödinger equation for the modulated EPO wave packet. The effects of the quantum diffraction, charged dust impurities and the effective e-h mass ratio on the propagation of linear dispersive EPOs, as well as on the modulational stability/instability of finite amplitude EPOs are examined. It is found that these parameters significantly affect the propagation of the EPOs as well as the nonlinear stability/instability domain of the wave vector, quite distinct from the classical and quantum electron-ion or electron-positron plasmas. The relevance of our investigation to semiconductor plasmas is discussed.