Anomalous hyperfine fields detected with the differential angular correlation method

Time differential perturbed angular distributions of nanosecond-levels of some rare earth nuclei embedded in a ferromagnetic host lattice have been measured. Coulomb excitation with 4–10 MeV α-particles and recoil implantation technique have been used. Some evidences have been found for anomalous hyperfine fields acting on the nucleus in a time period which cannot be resolved. On a time scale starting at about 1 nsec where details can be resolved, the hypothesis of a static hyperfine field parallel to the external polarizing field seems to be justified.     

Interactions in confined polariton condensates

We investigate the effect of interactions in zero-dimensional polariton condensates. The shape of the condensate wave function is shown to be modified by repulsive interactions with the reservoir of uncondensed excitons. In large micropillar cavities, when uncondensed excitons are located at the center, the condensate is ejected toward the pillar edges. The same effect results in the generation of optical traps in wire cavities. Once polariton condensates are spatially separated from the excitonic reservoir, spectral signatures of polariton-polariton interactions within the condensate are evidenced.     

Wetting of InP by indium- and indium-tin melts

Orientation dependent wetting of InP substrates by In- and In_xSn_1−x melts saturated with InP was studied using the sessile drop method. The contact angle was found to depend on the substrate orientation as follows: It is shown that a tin admixture to the indium melt improves the wetting behaviour. Additional to the dependence on substrate orientation it was found an anisotropic wetting on all investigated faces.