Angle-Resolved Photoemission Spectroscopy (ARPES) Program

The angle-resolved photoemission spectroscopy (ARPES) technique reveals the energy of the charged states of materials and their momentum dependence. ARPES is also highly sensitive to the symmetry of electronic states and their interactions with their environments. ARPES is a premier tool for understanding the emergent properties of superconducting, low-dimensional, or topological materials.

The ARPES program design and implement cutting-edge tools for low-temperature ARPES measurements, achieving world-leading capabilities in energy resolution (down to 1 meV after the beamline 4.0.3 upgrade in progress), spatial resolution (down to 100 nm), spin resolution, operando environments, and in situ synthesis. In close collaboration with our user community, we establish experimental protocols to allow exploration of the extensive parameter space and develop accompanying data analysis methodologies in three crosscutting research thrusts: 

• Bridging Length Scales–Investigating how properties emerge from fundamental constituents and evolve under confined geometries or applied fields, currents, and strain.
• Sample Synthesis and Control–Establishing robust sample pipelines to ensure that the highest-quality materials can be studied with the best probes.
• Spin, Topology, and Symmetry– Exploring the interplay between symmetry,  spin, and topology in magnetic and topological materials.

The ALS ARPES Program strives to create instrument environments and workflows that enable the highest-impact discovery-based science, especially in the area of quantum materials. We devise world-leading tools for low-temperature ARPES measurements with world-leading capabilities in energy resolution (down to 1 meV*), spatial resolution (down to 100 nm), spin resolution, operando environments, and in situ synthesis. We strive to support an agile, collaborative environment by working hand-in-hand with our user community to develop experimental protocols, navigate the extensive space of experimental degrees of freedom, and analyze data.

*After Beamline 4.0.3 upgrade in progress.