The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We study long wave polar optical modes at semiconductor surfaces (GaAs) and interfaces (GaAs/AlAs). We have considered also the cases in which the surface or interface is kept at a fixed electrostatic potential. The spectrum of excitations then shows significant differences. The existence of localized and resonant modes has been obtained by studying the spectral strength through the surface Green function matching (SGFM) method.