Samstämmigheten och spinn polarisering av sond vågor: at vidga vyerna inom spektroskopisk forskning

Tidsperiod: 2014-01-01 till 2017-12-31

Projektledare: Jan Rusz, Ján Rusz

Finansiär: Vetenskapsrådet

Bidragstyp: Projektbidrag

Budget: 3 000 000 SEK

Recent progresses with manipulating electron beam in transmission electron microscopes opened new frontiers of research. Use of the electron vortex beams, that is beams that carry an orbital angular momentum, brings a promise of measuring atom-specific magnetic moments at atomic resolution. Biprism with a Boersch plate prepares the electron beam as a coherent superposition of two convergent electron beams with tunable relative phase shift, also aiming to simplify the measurements of electron magnetic circular dichroism. Spin polarized electron beams will soon lead to pioneering new experimental techniques relying on spin-spin interactions between the sample and the probe beam.In order to maximize the output of these novel experimental techniques, we stress the demand for substantial progress in the theoretical understanding of the probe-sample interaction processes, which include fundamental questions related to interplay of dynamical diffraction effects, coherence of the probe beam, spin-dependent electronic transitions, relativistic effects and dynamical effects of the core-hole on the local electronic structure. Within this project we aim to address these challenges. The working tools will be state-of-the-art methods based on first principles calculations, high-performance computing and analytical models. Applications will include simulations of proof-of-concept experiments on magnetic samples utilizing vorticity, spin-polarization and coherence of the beam.