Novel k-space microscope for soft x-ray photoelectron spectroscopy of bulk materials and buried interfaces

• Applicants: Professor Dr. Ralph Claessen; Professor Dr. Gerd Schönhense
• Subject Area: Experimental Condensed Matter Physics
• Term: from 2017 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 326948345

This project aims at the development of instrumentation for soft x-ray angle-resolved photoelectron spectroscopy (SX-ARPES) based on the novel concept of momentum- or k-space microscopy. For this purpose we will construct such an instrument for operation at high photon energies, and test and use it at the I09 soft x-ray beamline of the Diamond Light Source. Based on a special objective lens, optimized for momentum-space imaging, the instrument facilitates true two-dimensional electronic bandstructure mapping of solids with dramatically enhanced detection efficiency. Thereby overcoming the notoriously low count-rates of conventional SX-ARPES, this novel approach will allow to make full use of the central advantage of high-energy photoemission, namely its much larger probing depth, providing access to the bulk electronic structure and to buried interfaces. As case in point we want to use selected oxide heterostructures as testbed and study their fascinating electronic interface properties. The k-space microscope proposed here has the potential to revolutionize the field of photoelectron spectroscopy and open its application to new areas previously not thought to be accessible by this technique.

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Major Instrumentation: hemispherical electron analyzer ; hexapod motorized with LHe cryostat ; microscope column (individually constructed from components)
• Instrumentation Group: 0260 Strahlungsmeßplätze (außer 033, 330-339, 405 und 615-619) ; 8550 Spezielle Kryostaten (für tiefste Temperaturen)
• Co-Investigator: Professor Dr. Hans-Joachim Elmers
• Cooperation Partners: Professor Tae-Hee Lee, Ph.D.; Dr. Jörg Zegenhagen