“One-cubed” ARPES User Facility at BESSY II

The growing significance of the precise spectroscopic tools in condensed matter physics is to a very considerable degree indebted to the recent advances in instrumentation. Angle-resolved photoemission has strongly benefitted from the introduction of angle-multiplexing analyzers at the end of last century [1 Martensson, N. 1994. Journal of Electron Spectroscopy and Related Phenomena, 70: 117[Crossref], [Web of Science ®] , [Google Scholar]], which virtually turned the technique from a band-mapping tool into a sophisticated many-body spectroscopy. It was soon realized that in order to deliver detailed and undistorted information about the spectral function – the ultimate output of ARPES – one needs to thoroughly explore the parameter space of the experiment. Assuming that all the photoelectrons are detected, these parameters are basically the photon energy and angles of incidence of the linearly polarized light. It is the combinations of these quantities which can strongly suppress the photocurrent from a given sample via the matrix element effects. For a modern ARPES experiment it is therefore desired to have a full control of photon energy and polarization, which inevitably implies the use of synchrotron radiation.