Conveners
Condensed matter
- Stefano Bonetti (Stockholm university)
Condensed matter
- Stefano Bonetti (Stockholm university)
On which timescale do the band structure and spin polarization of a ferromagnet change after femtosecond laser excitation and how do they affect the magnetization dynamics? To answer these questions we perform time-, spin-, and angle-resolved photoemission experiments with optical laser pulses and higher-order harmonic radiation.
We have studied ultrafast demagnetization in the local-moment...
In non-metallic solids, heat is carried primarily by acoustic phonons. At cryogenic temperatures, the phonon mean free path (MFP) can be large, and ballistic propagation of heat over macroscopic distances has been well documented in the “phonon imaging” studies. At room temperature, the MFP of thermal phonons is small and heat typically propagates via diffusion: once the thermal conductivity...
Free-electron lasers (FELs) are currently the only ultrashort-pulsed photon sources that can provide sufficient photon flux for time-resolved pump-probe solid-state photoemission measurements in the soft and hard x-ray regime. In principle, FELs enable powerful combinations of photoemission techniques, augmented by femtosecond time resolution, in a single experiment. We particularly envision a...
Identifying the degrees of freedom that lead to the emergence of superconductivity in iron-based materials remains the subject of active research. Amongst spin-driven scenarios, it has also been suggested that electron-electron correlations enhance the electron-phonon coupling in iron chalcogenides and related pnictides, but direct experimental verification has been lacking.
Measurements of...
I will describe recent experiments using ultrafast electron diffraction and x-ray free electron lasers to probe light-induced structural dynamics in layered transition metal dichalcogenide materials. In particular the focus of this talk will be terahertz-driven atomic-scale responses in WTe2 and related materials. We show, via the measurement of structure factor changes in >200 Bragg...
