INTERFACE OPTICAL PHONONS NEAR PERFECTLY CONDUCTING BOUNDARIES AND THEIR COUPLING TO ELECTRONS

The interface optical phonon, are described for a GaAs/AlAs system enclosed within metal (or superconductor) boundaries. The requirement that the electrostatic potential associated with these modes vanishes at these boundaries alters the dispersion of the interface modes, especially that of the antisymmetric vibrations. The interaction of electrons with these modes is also considered, and a reduction in the rates is obtained, in particular, when the AlAs width is less than the GaAs width. As such, it is demonstrated that tampering with the long-range Coulomb fields of the optical phonons by external means, here by the proximity of perfectly conducting interfaces, leads to a weakening of the Frohlich interaction by effectively imposing a lower bound on the in-plane wave vector which arises in the coupling function. This lower bound is equal to the reciprocal of the AlAs width. In the special case of a metal/GaAs/metal device, the carriers do not couple to interface modes.