Plasmon‐enhanced sound amplification in piezoelectric semiconductors under a strong magnetic field

The effect is considered of a strong dc magnetic field upon the contribution to sound amplification in piezoelectric semiconductors arising from the energy conversion mechanism “plasmon + + carrier → phonon + carrier”. An explicit expression is derived for the amplification coefficient. It is shown that under suitable conditions such contribution largely differs from that in the absence of a magnetic field both in the strength of the effect and in the angular distribution of the emitted phonons. A physical interpretation of the results is presented.