Time- and polarization-resolved extreme ultraviolet momentum microscopy.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spectroscopy

Background:

• Quantum materials exhibit complex electronic behaviors crucial for next-generation technologies.
• Understanding these materials requires advanced spectroscopic techniques capable of probing their electronic structure with high resolution.
• Existing methods often lack the combined temporal, energy, and momentum resolution needed to capture dynamic quantum phenomena.

Purpose of the Study:

• To develop and characterize a novel instrument for advanced photoemission spectroscopy.
• To enable time- and angle-resolved studies of quantum materials with multimodal dichroism capabilities.
• To investigate the orbital and quantum geometrical properties of non-equilibrium quantum materials.

Main Methods:

• Integration of an ultrafast, polarization-tunable monochromatic extreme ultraviolet (XUV) beamline with a next-generation momentum microscope.
• Utilization of advanced electron optics, including a novel front lens, for versatile operation.
• Implementation of small beam footprints and aperture-based region selection for enhanced spatial resolution.
• Performance of time- and angle-resolved photoemission spectroscopy with multimodal photoemission dichroism.

Main Results:

• Achieved an energy resolution of 44 meV and a temporal resolution of 144 fs.
• Demonstrated simultaneous detection of the full surface Brillouin zone over an extended binding energy range.
• Successfully performed linear, Fourier, and circular dichroism measurements on photoexcited 2D materials.
• Validated the instrument's capability for high-resolution spatial mapping using small XUV beam footprints.

Conclusions:

• The developed instrument represents a significant advancement in the study of quantum materials.
• It enables unprecedented time-, energy-, and momentum-resolved investigations of electronic structure dynamics.
• This capability will accelerate the discovery and understanding of novel quantum phenomena and material properties.