The UEM’s application is for investigating ultrafast (sub-picosecond) structural and chemical dynamics in materials at the nanoscale using electrons, an exciting area of emerging science.
Our UEM combines the following features:
- a tunable femtosecond laser with a high repetition rate
- multiple routes to produce a pulsed electron beam
- a synchronous laser-pumped, pulsed transmission electron microscope that is outfitted with high-sensitivity cameras and electron energy filtering.
This tool, which we have carefully designed, opens the door to an area of scientific understanding not available with any standard electron microscope, namely, the understanding of fast (sub-picosecond to nanosecond) dynamics and short-lived metastable phases in materials with sub-nanometer spatial resolution. It represents a key analytical tool that can deliver insights on ultrafast structural and chemical changes to a wide range of systems.
In the coming years, by developing ultrafast electrical and mechanical triggering mechanisms, we expect to develop novel sample environments and routes of sample excitation with fundamental and device relevance. Combined with ultrafast probing, this will permit insights into non-equilibrium phenomena of electric field and strain. For example, one can explore the time-varying impact of strain produced by acoustic phonon modes in materials and systems of interest for quantum information science, such as vacancy defects in diamond or silicon carbide.
There are many areas of nanoscience where the UEM can be highly valuable in advancing our understanding of transient processes, such as in exciton localization, short-lived metastable phases, photo-induced segregation, dynamics in topological materials, plasmonic systems, molecular motors, and magnetic fluctuations, to name a few. Together with theoretical modeling, the UEM will provide unprecedented understanding of nanomaterials for the nanoscience community.
- Temporal resolution: approximately 1 ps
- Spatial resolution: approximately 1 nm
- Energy resolution: approximately 1 eV
- Pump laser wavelengths: 515 nm, 325-450 nm, 650-900 nm, 1030 nm, and 1200-2000 nm
- Repetition rate: 10-500 kHz (fs laser), 1-100 kHz (ns laser)
- Technical contacts: Thomas Gage (firstname.lastname@example.org) and Haihua Liu (email@example.com)