Speaker
Description
Collective dynamics at the nanoscale in condensed matter is important for advancing both fundamental science and modern technology. The study of heat transport processes, vibrational modes or magnetization dynamics in the sub-100 nm length-scales greatly benefit from experimental tools able to probe such dynamics on the relevant timescale (i.e. ps and sub-ps) without relying on ad hoc sample’s nanostructuration.
In this talk we will present an overview of a “contact-less” approach for studying nanoscale dynamics, where the sensitivity to the sub-100 nm length-scale is granted by the use of extreme ultraviolet transient gratings (EUV TG). We will briefly discuss the application of this new experimental tool (available at the FERMI free electron laser facility in Triste; Italy) for the study of a number of dynamical phenomena:
i) nanoscale thermal transport in thin membranes [1]
ii) phonon dynamics in nanophononic materials, surfaces and confined media [2]
iii) ultrafast demagnetization, magnons and all-optical magnetization switching [3]
In addition, we will present a few other sample applications of EUV TG, which hold the potential for becoming relevant experimental tools, such as: resonant self-diffraction [4] and polarization gratings [5].
References
[1] F. Bencivenga et al., “Nanoscale transient gratings excited and probed by extreme ultraviolet femtosecond pulses”, Science Adv. 5, eaaw5805 (2019).
[2] M. Hadi et al., “The effect of echoes interference on phonon attenuation in a nanophononic membrane”, Nat. Commun. 15, 1317 (2024); L. Foglia, R. Mincigrucci et al., “Extreme ultraviolet transient gratings: A tool for nanoscale photoacoustics”, Photoacoustics 29, 100453 (2023); A.A. Maznev et al., “Generation and detection of 50 GHz surface acoustic waves by extreme ultraviolet pulses”, Appl. Phys. Lett. 119 (2021).
[3] P. Miedaner et al., “Excitation and detection of coherent nanoscale spin waves via extreme ultraviolet transient gratings”, Science Adv. 10, adp6015 (2024); F. Steinbach et al., “Exploring the fundamental spatial limits of magnetic all-optical switching”, Nano Lett. 24, 6865 (2024); D. Ksenzov et al., “Nanoscale Transient Magnetization Gratings Created and Probed by Femtosecond Extreme Ultraviolet Pulses”, Nano Lett. 21, 2905 (2021).
[4] A. Maznev et al, “Resonant self-diffraction of femtosecond extreme ultraviolet pulses in cobalt” (submitted; arxiv.org/abs/2505.07168).
[5] L. Foglia et al. “Nanoscale transient polarization gratings”, Nat. Commun. 15, 10742 (2024).