Multispectral time-resolved energy-momentum microscopy using high-harmonic extreme ultraviolet radiation

A 790-nm-driven high-harmonic generation source with a repetition rate of 6 kHz is combined with a toroidal-grating monochromator and a high-detection-efficiency photoelectron time-of-flight momentum microscope to enable time- and momentum-resolved photoemission spectroscopy over a spectral range of 23.6-45.5 eV with sub-100 fs time resolution. Three-dimensional (3D) Fermi surface mapping is demonstrated on graphene-covered Ir(111) with energy and momentum resolutions of & LSIM;100 meV and & LSIM;0.1 & ANGS;(-1), respectively. The tabletop experiment sets the stage for measuring the k(z)-dependent ultrafast dynamics of 3D electronic structure, including band structure, Fermi surface, and carrier dynamics in 3D materials as well as 3D orbital dynamics in molecular layers. (C) 2022 Author(s).All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY)license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

A 790-nm-driven high-harmonic generation source combined with a toroidal-grating monochromator and a high-detection-efficiency photoelectron time-of-flight momentum microscope enables time- and momentum-resolved photoemission spectroscopy. Three-dimensional Fermi surface mapping is demonstrated on a graphene-covered surface, providing a basis for studying ultrafast dynamics.