Development of Photoemission Microscopy in Real and Momentum Spaces

This article reports the development of Imaging-type Spin-Resolved PhotoEmission Microscopy (iSPEM), an instrument enabling spin-resolved photoelectron imaging in both real and momentum spaces. The system combines a photoelectron emission microscopy (PEEM)-based electron lens with an imaging double-energy analyzer, enabling rapid switching between real- and momentum-space modes with energy-resolved imaging. By incorporating a multichannel spin detector, iSPEM achieves significantly higher efficiency in spin-polarization measurements than conventional spin-resolved photoemission spectroscopy. A delay-line detector for time-of-flight analysis further enables efficient acquisition of multidimensional datasets. The instrument allows visualization of electronic states in submicrometer-scale and inhomogeneous samples, including polycrystals and magnetic domain structures. Representative demonstrations highlight its potential for studying quantum, magnetic, and low-dimensional materials, as well as spin-based devices.