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Abstract
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The quantum hydrodynamic model is used to
investigate the arbitrary degenerate electron/hole stream instabilities in ballistic semiconductors or semiconductor plasmas
(semiplasmas) for a wide range of impurity doping, number
density, and temperatures. It is observed that, while the instability
in classical plasma regime is always of single k-range type,
the double-range instability can occur in degenerate plasma
regime. Different types of carrier counter-streaming instabilities
are classified and parametrically studied in arbitrarily doped
ballistic semiconductors. The parametric study of counter-stream
instability in silicon at room temperature shows that the doping
scheme has fundamental effect on electron–electron and hole–
hole instabilities but no effect on electron–hole instability. Other
parameters, such as the electron temperature and stream speed,
have significant effects on the unstable wavenumber range and
the growth rate. It is remarked that the electron stream in ntype semiconductors becomes unstable at somewhat lower limit
of the stream speed than that of holes in a p-type silicon
semiconductors. A description based on the energy exchange
between unstable modes is given for different instability types.
It is found that the instability in asymmetric doped semiconductors (electron–electron and hole–hole) is of symmetric type
without energy exchange between the modes, while, for symmetric doped semiconductors (electron–hole), it is of asymmetric type
with the energy exchange. Finally, it is found that the electron and
hole spin exchange–correlation effects enhance the two-stream
instability.
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