XUV Spectroscopy Fundamentals: Advantages and Developments for Probing Surface and Interfacial Charge Carrier Dynamics

Transient extreme ultraviolet (XUV) spectroscopy has become an increasingly popular tool in developing ultrafast science advancements. Probing core-to-valence electronic transitions, XUV light sources mimic many of the benefits of traditional X-ray studies (element specificity, oxidation and spin state sensitivity, etc.), while additionally performing on a femtosecond timescale. Combining these properties with a reflection geometry introduces a unique surface sensitivity that independently probes processes constrained to surfaces and interfaces from bulk character.

Experimentally, XUV light can be produced in a laboratory-based setting through the process of tabletop high harmonic generation. Interesting vacuum and optical considerations will be discussed that are critical to successful XUV science. The qualities of XUV spectroscopy attract applications such as photochemistry (charge control) and ultrafast magnetism (spin control). We  highlight recent developments from the XUV community and reveal successes and upcoming directions for the field.