FUCHS-KLIEWER INTERFACE POLARITONS AND THEIR INTERACTIONS WITH ELECTRONS IN GAAS/ALAS DOUBLE HETEROSTRUCTURES

A new theoretical approach to describe the interaction of electrons with Fuchs-Kliewer (FK) interface phonon polaritons is outlined. The quantized vector potential A of the FK modes in GaAs/AlAs quantum wells is derived and employed via the minimal coupling interaction (-e/m*)A.p to evaluate the intersubband and intrasubband relaxation rates. A novel resonance in the intersubband rate is predicted and shown to be intimately related to the FK mode dispersion. As for the intrasubband rate, it is shown that for small well widths the AlAs-like FK interface mode is crucial for relaxing the carrier energy in GaAs/AlAs systems.