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Anisotropic hot electron emission from fullerenes.
J O Johansson1, J Fedor, M Goto
1EaStCHEM, School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, Scotland.
The Journal of Chemical Physics
|May 8, 2012
Summary
Fullerenes C(60) and C(70) exhibit unique electron behavior when ionized by laser pulses. Thermal electrons show higher kinetic energy along the laser polarization, indicating an additional energy "kick" during emission.
Area of Science:
- Physical Chemistry
- Molecular Physics
- Quantum Mechanics
Background:
- Fullerenes (C60 and C70) are carbon allotropes with unique electronic properties.
- Laser-matter interactions are crucial for understanding electron dynamics in molecules.
- Photoelectron spectroscopy is a key technique for probing electronic structures.
Purpose of the Study:
- To investigate the kinetic energy and angular distribution of photoelectrons from fullerenes ionized by ultrashort laser pulses.
- To elucidate the mechanisms behind the observed thermal electron kinetic energy anisotropy.
Main Methods:
- Utilizing 800 nm laser pulses with varying durations (120-1000 fs).
- Analyzing photoelectron spectra to determine kinetic energy distributions and angular anisotropy.
- Comparing electron emission along and perpendicular to laser polarization.
Main Results:
- Photoelectron spectra revealed thermal electron kinetic energy distributions for C(60) and C(70).
- A significant angular anisotropy was observed, with higher electron temperatures along the laser polarization direction.
- This anisotropy is attributed to phase-uncorrelated emission and potential vector potential "kicks".
Conclusions:
- The study explains the observed electron kinetic energy anisotropy in laser-ionized fullerenes.
- The findings highlight the influence of laser field vector potential on electron emission dynamics.
- This research contributes to understanding electron behavior in intense laser fields.
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