Free-electron lasers and high-harmonic-generation table-top systems are new sources of
extreme-ultraviolet to hard X-ray photons, providing ultrashort pulses that are intense …

The recent construction of free electron lasers allows extending laboratory-based laser
experiments to shorter wavelengths, accessing wavevectors typical of nanoscale dynamics …

Collective lattice dynamics determine essential aspects of condensed matter, such as elastic
and thermal properties. These exhibit strong dependence on the length-scale, reflecting the …

Advances in develo** ultrafast coherent sources operating at extreme ultraviolet (EUV)
and x-ray wavelengths allow the extension of nonlinear optical techniques to shorter …

Optical-domain transient grating (TG) spectroscopy is a versatile background-free four-wave-
mixing technique that is used to probe vibrational, magnetic and electronic degrees of …

High-frequency surface phonons have a myriad of applications in telecommunications and
sensing, but their generation and detection have often been limited to transducers …

We use femtosecond extreme ultraviolet pulses derived from a free electron laser to excite
and probe surface acoustic waves (SAWs) on the (001) surface of single crystal SrTiO 3 …

Microscale energy transport processes are crucial in microelectronics, energy-harvesting
devices, and emerging quantum materials. To study these processes, methods that can …

Non-equilibrium phonons have been discussed for almost six decades. Here, the nature of
the longitudinal optical mode, particularly in polar materials, is discussed along with its …

Driving four-wave mixing (FWM) processes with extreme ultraviolet (EUV) pulses could
enable experimental approaches that have the potential to provide unique information on …