Objectif Sources of polarized electrons based on photoelectronemission are very powerful tools in solid state physics, in atomic physics, in elementary particle physics, as well as in nuclear physics. In all these fields the number of investigations using beams of polarized electrons is increasing rapidly, because new insights into fundamental spin-dependent interactions between electrons and matter are possible. Up to now photocathodes made from bulk GaAs or its relatives have been used primarily for producing sources of polarized electrons. This material allows the emission of electrons spinpolarized to a degree of 50% only. New cathodes based on strained layers of III-V-semiconductors or on III-V-superlattice structures give polarization values above the 50% limit. First promising results are reported in the literature by American and Japanese groups. The goal of this project is the development of new types of photoemitters of polarized electrons. Encouraging data have already been produced. Investigations of strained GaAs- and GaAsP-cathodes produced by the loffe Institute in St. Petersburg reveal a spinpolarization of emitted electrons up to 88%, while the second Russian group in Novosibirsk has developed InGaAsP-cathodes that produce photoelectrons with a degree of polarization of 55%, so far at a high quantum efficiency. In the framework of the project the following work will be done: application of semiconductor photocathodes in sources of polarized electrons attached to an electron accelerator; measurement of spinpolarization spectra, of yield spectra, and of life time of photocathodes developed in the project; research on fundamental physics of photoelectron emission from solids; development of new schemes for the production of highly polarized electrons; growth of strained layer III-V-photocathodes and III-V-superlattice structures by MOCVD-techniques; growth of GaAsP-cathodes with optimum of spinpolarization of emitted electrons tuned to powerful laser radiation; theoretical calculations of semiconductor heterostructures suited to spinpolarized photoelectron emission; growth of semiconductor heterostructures applied in spinpolarized photoelectron emission by using liquid phase epitaxy; research on spinpolarized photoemission from III-V-semiconductor compounds; and study of time evolution of the photoemission process. Programme(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Thème(s) 15 - Condensed Matter Physics Appel à propositions Data not available Régime de financement Data not available Coordinateur JOHANNES GUTENBERG UNIVERSITÄT MAINZ Contribution de l’UE Aucune donnée Adresse Staudinger Weg 7 55099 Mainz Allemagne Voir sur la carte Coût total Aucune donnée Participants (6) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire Ecole Polytechnique France Contribution de l’UE Aucune donnée Adresse 91128 Palaiseau Voir sur la carte Coût total Aucune donnée Politecnico di Milano Italie Contribution de l’UE Aucune donnée Adresse Piazza Leonardo da Vinci 32 20133 Milano Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée Russian Academy of Sciences Russie Contribution de l’UE Aucune donnée Adresse 194021 St. Petersburg Voir sur la carte Coût total Aucune donnée Russian Academy of Sciences - Siberian Branch Russie Contribution de l’UE Aucune donnée Adresse 630090 Novosibirsk Voir sur la carte Coût total Aucune donnée St. Petersburg State Technical University Russie Contribution de l’UE Aucune donnée Adresse 195251 St. Petersburg Voir sur la carte Coût total Aucune donnée Stichting voor Fundamenteel Onderzoek der Materie Pays-Bas Contribution de l’UE Aucune donnée Adresse 1009 DB Amsterdam Voir sur la carte Coût total Aucune donnée