Exploiting Soft X-ray ARPES to Looking Beyond the Surface in Correlated Electron Systems

Speaker:

Jessica McChesney, physicist Argonne National Laboratory

Description:

Taking advantage of the unique niche that soft x-ray ARPES provides, i.e. bulk sensitivity while maintaining momentum resolution, we explore the bulk band structure of several classes of strongly correlated materials. These materials, which include topological insulators, heavy fermions and complex oxides, have very rich phase diagrams where small changes in carrier concentration, such as that at the vacuum/surface interface, can significantly alter the band structure. These results showcase the performance of the intermediate energy x-ray (IEX) beamline at the Advanced Photon Source, Argonne National Laboratory, where the photon energy can be tuned from 250 to 3000 eV in order to exploit the varying surface/bulk sensitivity. In addition, this energy range provides access to many electronically relevant absorption edges where the resonance process is used to enhance the sensitivity for buried interfaces and dilute signals, in addition to further define the character of the bands.