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

Area of Science:

• Condensed Matter Physics
• Materials Science
• Synchrotron Radiation Science

Background:

• Angle-resolved photoemission spectroscopy (ARPES) is crucial for understanding electronic structures.
• Spatial resolution in ARPES is needed to study mesoscale devices and quantum materials.
• Existing techniques may lack the precision for probing microscopic domains.

Purpose of the Study:

• Introduce the AU-SGM4 extreme ultraviolet beamline for spatially resolved ARPES.
• Demonstrate its capability to analyze electronic structures of small material domains.
• Showcase its application in studying operational devices and novel quantum materials.

Main Methods:

• Utilized an achromatic elliptical capillary optic for focusing extreme ultraviolet synchrotron light to a 4 μm spot size.
• Employed a custom 11-degree-of-freedom piezoelectric motor system for precise sample and optic positioning.
• Operated within a low photon energy range (12-150 eV) for detailed electronic structure probing.

Main Results:

• Achieved exceptional beam positioning stability across the entire photon energy range.
• Successfully performed simultaneous ARPES measurements and in situ gating of a graphene device.
• Probed microscopic domains of MnBi6Te10, obtaining energy- and momentum-dependent dispersion for each domain.

Conclusions:

• The AU-SGM4 beamline provides unprecedented spatial resolution for ARPES.
• It enables detailed electronic structure investigations of mesoscale devices and quantum materials.
• This advancement facilitates the study of complex materials at the microscale.