THERMOELECTRIC AMPLIFICATION OF PHONONS IN CYLINDRICAL QUANTUM-WELL WIRES

The damping coefficient gamma(q) of acoustical phonons interacting wit h electrons confined in a cylindrical quantum well wire subjected to a n external temperature gradient is calculated. The phonon amplificatio n coefficient (gamma(q)>0) under certain conditions for material and t emperature gradient is obtained. In the size quantum limit (ground sta te), in nondegenerate semiconductors, the amplification coefficient is found to be enhanced over its bulk value for the whole range of the r adius of the wire. It is also found that phonon amplification is obtai ned for smaller temperature gradients as compared with their correspon ding values in bulk. An application is made for AlxGa1-xAs/GaAs quantu m well wires. (C) 1998 American Institute of Physics.