Abstract
We report a novel approach for coherent multi-photon photoemission in the entire Brillouin zone with infrared light that is readily implemented in a laboratory setting. We excite a solid state material, Ag(110), with intense femtosecond laser pulses to excite higher-order multi-photon photoemission; angle-resolved electron spectroscopic acquisition records photoemission at large in-plane momenta involving optical transitions from the occupied to unoccupied bands of the sample that otherwise might remain hidden by the photoemission horizon. We propose this as a complementary ultrafast method to time- and angle-resolved two-color, e.g. infrared pump and extreme ultraviolet probe, photoemission spectroscopy, with the advantage of being able to measure and control the coherent electron dynamics.
Highlights
Time- and angle-resolved two-photon photoemission spectroscopy (TR-2PP) enables mapping the energy and momentum (k||, k⊥)-resolved electronic structure and dynamics of the occupied and unoccupied electronic bands of solids [1,2,3]
The photoemission horizon refers to the kinetic energy in the surface parallel motion, Ek||in = meħ2k|2|⁄2, which cannot do work against the work function because k|| of electrons passing through a solidvacuum interface is conserved [18,19]
Table-top high-harmonic generation (HHG) sources pumped by femtosecond laser amplifiers can supply ultrafast XUV light pulses with ħ >20eV energy at high repetition rates [20,21,22,23,24]; such laser systems have been applied to perform time- and angle-resolved photoelectron spectroscopy (TR-ARPES), where an intense infrared or optical pumppulse excites the electronic system, and an XUV-probe pulse interrogates its impact on the electronic band structure of the sample
Summary
Time- and angle-resolved two-photon photoemission spectroscopy (TR-2PP) enables mapping the energy and momentum (k||, k⊥)-resolved electronic structure and dynamics of the occupied and unoccupied electronic bands of solids [1,2,3]. To access the entire Brillouin zone, photoelectrons must be excited to sufficiently high energies to overcome the photoemission horizon.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
