Abstract: Nanofabrication today spans atomic level precision to hierarchically organized structures reaching up to microns. Nanoscale material properties are profoundly different from their bulk counterparts, and when combined with metamaterial approaches, systems can be engineered with properties unavailable in naturally occurring substances. These effects have applications from nanoelectronics to thermoelectrics to nanoparticle-based cancer therapies. However, the full capabilities of these materials have not yet been realized due to the difficulty of studying functional nanosystems.
In this talk, I will present our work studying the ultrafast thermal and elastic dynamics of nanoscale materials at their intrinsic length and time scales, via the diffraction of extreme ultraviolet (EUV) beams, generated coherently by using tabletop high-harmonic generation. For nanoscale thermal transport, we find that the highly nondiffusive cooling of confined heat sources can be tuned back to within a factor of two of the faster, diffusive prediction, simply by bringing the heat sources closer together. For nanoscale elastic properties, we fully characterize hydrogenated thin films down to 10 nm in thickness. We compare and contrast how thickness and hydrogenation change the elastic properties of these films, which are relevant to integrated circuit fabrication. Finally, I will briefly describe efforts with both the FERMI free-electron laser and with our tabletop setup to generate an EUV transient grating, which can excite dynamics at the deep nanoscale in a fully noncontact modality. This would enable nondestructive and in situ studies of a wide variety of functional nanosystems.