Development of the laser based μ-SARPES machine at HiSOR

Angle-resolved photoemission spectroscopy (ARPES) is a powerful tool to directory observe the electronic structure of solids. In recent years, micro-ARPES [1], which is combined with a micro spot light source, has attracted much attention, since it is found to be very useful to explore the electronic states in topological materials [2], phase-separated correlated systems [3] and transcription samples [4].

 Spin-ARPES (SARPES) [5] enables us to detect not only the energy and momentum but also the photoelectron spin owing to recent development of spin detectors. However, micro-SARPES measurement has never been reported so far, because of difficulties of the spin detection and its combination technique.

 In this poster, I will describe the-state-of-the-art micro-SARPES machine using laser source (hν= 6.39 eV) at Hiroshima Synchrotron Radiation Center (HiSOR). Owing to the photoelectron analyzer equipped with the electron deflector function and two VLEED type spin detectors, one can map out the spin vector onto the band image without rotating a sample. The spatial resolution with 5 micrometers and long-time stability have been achived. We will also report some examples of measurements to show the performance of our apparatus.

[1] H. Iwasawa et. al., Ultramicroscopy, 182, 85 (2017).

[2] R. Noguchi, et. al., Nature, 566, 518 (2019).

[3] K. Kuroda et. al., Nature Communication, 11, 2888 (2020).

[4] I. Cucchi, et. al. Nano letter, 19, 554 (2019).

[5] T. Okuda et. al., J. Phys. Condens. Matter, 29, 483001 (2018).