Abstract
The temporal evolution of the exchange-split -like valence bands of the -ferromagnet gadolinium after femtosecond laser excitation has been studied using angle-resolved photoelectron spectroscopy based on high-order harmonic generation. The ultrafast drop of the exchange splitting reflects the magnetic response seen in femtosecond magnetic dichroism experiments. However, while the minority valence band reacts immediately, the response of the majority counterpart is delayed by 1 picosecond and is only half as fast. These findings demonstrate that laser excitation drives the valence band structure out of magnetic equilibrium.
- Received 10 April 2012
DOI:https://doi.org/10.1103/PhysRevLett.109.057401
© 2012 American Physical Society