Low Frequency Hybrid Instability In Quantum Magneto Semiconductor Plasmas

Abstract

The electrostatic low-frequency hybrid wave generated by the classical electron beam in electron-hole plasma is discussed here using the quantum hydrodynamic model (QHD). Semiconductors provide a suitable source to investigate such waves because of the mass asymmetry of electrons and holes which leads to charge separation and oscillating electric field in the electron-hole plasma. This oscillating electric field produces various electrostatic modes and drives instability in electron-hole plasma. Many quantum effects are considered such as quantum Bohm potential, perturbed Fermi pressure at T>0K, exchange-correlation effects. To study the behavior of wave and instability growth rate, the derived dispersion relation is applied to GaAs compound semiconductor. The dynamics of the plasma species like electrons, holes, and beam electrons play an important role in the propagation and growth rate of the wave. Increasing the electron to hole number density causes a blue shift in the spectrum. The increase in electron beam speed will increase the instability whereas an increase in beam temperature will decrease the instability due to a larger amount of excited particles. Moreover if the angle between the LHW wavevector and the x-axis or the hole cyclotron frequency increases, the instability increases due to the stronger magnetic field.