The following seminar was held
Date and Time: April 10,2025 (Thu.) 10:00-11:30
Venue:Room 913, Building 1, Faculty of Science, The University of Tokyo, and via ZOOM (Advance registration required for both)
Speaker: Professor Peter Hommelhoff (Physics Department, Friedrich-Alexander University, Erlangen, Germany/ Faculty of Physics, Ludwig-Maximilian University, Munich, Germany)
Title Ultrafast control over electrons-in free space beams, inside of matter and at needle tips
Optical fields and electrons can be efficiently coupled. We show three experiments in which we could gain new insights and reach new levels of electron control by focusing ultrashort, often phase-controlled few-cycle pulses at (1) photonic nanostructures for electron acceleration, (2) graphene and (3) sharp needle tips. (1) With properly designed quasi-periodic nanostructures, we could demonstrate complex electron phase space control at optical frequencies. This allowed us to guide and accelerate electron bunches through the 225nm narrow channel of a 500µm long nanophotonic accelerator structure, obtaining an energy increase from 28 to 40 keV. (2) In graphene and at the graphene-gold interface, we could demonstrate strongfield coherent electron dynamics, allowing us to show a first logic gate potentially operating at petahertz frequencies. (3) At sharp needle tips, we can now perform precision attosecond physics measurements. For example, we measured the electron emission with an error bar as small as 30 attoseconds. Last, I will show chip-based guiding of electrons, resulting in novel low-energy electron resonators.
Language: English
Host Fqaculty Member: Kazuyuki SAKAUE
Contact:
sec-utripl@utripl.u-tokyo.ac.jp
Note: This seminar is open to the public. Participants are kindly requested to provide their name, affiliation, and email address upon registration.