Spin-resolved photoemission from Xe-adlayers on Pd(111)

Xe-adsorbates on Pd(111) in the coverage region from one layer up to a Xe(111) crystal with first layer Xe-Xe distances comparable to bulk Xe are studied by spin-resolved photoemission. Normally incident circularly polarized synchrotron radiation from BESSY (Berlin) is used and normally emitted electrons are analyzed. No dispersion with photon energy can be found for a system of two Xe-layers. The spin-polarization component measured along the direction of light points to a changing symmetry of the final states. Their symmetry is atom-like for a one-layer system and bulk-like for two and more layers. The initial state symmetry is examined by excitation and decay of excitonic states and is found to be the same for two Xe-layers as for one single Xe-layer. The degeneracy of the valence levels connected with the high symmetry of the Γ-point in bulk Xe can be observed for a system of much more than 5 Xe-layers thickness