SMALL SIGNAL POWER THEOREM ON DRIFTING CARRIERS AND ELASTIC WAVES IN SOLIDS WITH NON-MAGNETISM APPLICATION TO PIEZOELECTRICITY

The small signal power theorem is applied to drifting carriers and elastic waves in three dimensions, commencing with Maxwell-Minkowski's equations, which include the effects of an external dc magnetic field as well as those of collisions and compressibilities. Consequently the findings reveal the clear informations of the power transfer among the systems concerned. The theory is applied to learn a give-and-take on gain mechanisms in one dimension in piezoelectric semiconductors as an example, subjected or not to an external dc magnetic field, where a role of each system in power distributions is discussed. Especially the definition of the threshold field involved in an amplification of elastic waves and electromagnetic waves are suggested and argued in contrast with an attenuation constant. © 1968, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.