A spatial- and angle-resolved photoemission spectroscopy beamline based on capillary optics at ASTRID2.

Abstract

Angle-resolved photoemission spectroscopy (ARPES) with spatial resolution is emerging as a powerful investigative tool for the study of operational mesoscale devices and quantum materials. Here, we introduce AU-SGM4, an extreme ultraviolet beamline based at the ASTRID2 synchrotron, which is designed around an achromatic elliptical capillary optic that focuses the synchrotron light down to a lateral beam spot size of 4 μm. The beamline offers a low photon energy range of 12-150 eV, ideal for probing detailed energy- and momentum-resolved electronic structures of materials. We utilize a custom-made piezoelectric motor system with 11 degrees of freedom for precisely moving the sample and capillary optic. We demonstrate exceptional stability in beam positioning on samples across the entire available photon energy range. To showcase the capabilities of the AU-SGM4 beamline, we present simultaneous ARPES measurements and in situ gating of a graphene device and probe the nominally inaccessible microscopic-sized domains of MnBi6Te10 to obtain the energy- and momentum-dependent dispersion for each domain.