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

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