The effect of a high-frequency electric field on hypersound amplification in a superlattice
S Y Mensah; F K A Allotey; S K Adjepong; S Y Mensah; ICTP, Trieste, Italy; F K A Allotey; ICTP, Trieste, Italy; S K Adjepong; ICTP, Trieste, Italy
Журнал:
Journal of Physics: Condensed Matter
Дата:
1994-05-09
Аннотация:
Propagation of hypersound in a semiconductor superlattice in the presence of an external electric field of the form E=E<sub>0</sub>+E<sub>1</sub> cos( omega t) has been studied theoretically. The analytical expressions obtained for the absorption coefficient are presented graphically. It is observed that in the absence of an AC electric field the dependence of Gamma on E<sub>0</sub> is non-linear unlike the homogeneous bulk material where the dependence of Gamma on E<sub>0</sub> is linear. The inclusion of an AC electric field affects the relation between Gamma and E<sub>0</sub> depending on the values of E<sub>1</sub> and omega tau . For a given E<sub>1</sub>, the peaks of the curve of Gamma against E<sub>0</sub> decrease, shift and eventually oscillate for increasing values of omega tau , i.e. from or <<1 to omega tau >>1.
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