Enhanced Photon-Phonon Interaction in WSe Acoustic Nanocavities.

Acoustic nanocavities (ANCs) with resonance frequencies much above 1 GHz are prospective to be exploited in sensors and quantum operating devices. Nowadays, acoustic nanocavities fabricated from van der Waals (vdW) nanolayers allow them to exhibit resonance frequencies of the breathing acoustic mode up to ∼ 1 THz and quality factors up to ∼ 10. For such high acoustic frequencies, electrical methods fail, and optical techniques are used for the generation and detection of coherent phonons.

Ultrafast magnetoacoustics in Galfenol nanostructures.

Phonons and magnons are prospective information carriers to substitute the transfer of charge in nanoscale communication devices. Our ability to manipulate them at the nanoscale and with ultimate speed is examined by ultrafast acoustics and femtosecond optomagnetism, which use ultrashort laser pulses for generation and detection of the corresponding coherent excitations. Ultrafast magnetoacoustics merges these research directions and focuses on the interaction of optically generated coherent phonons and magnons.

Coherent Phononics of van der Waals Layers on Nanogratings.

Strain engineering can be used to control the physical properties of two-dimensional van der Waals (2D-vdW) crystals. Coherent phonons, which carry dynamical strain, could push strain engineering to control classical and quantum phenomena in the unexplored picosecond temporal and nanometer spatial regimes. This intriguing approach requires the use of coherent GHz and sub-THz 2D phonons.

Protected Long-Distance Guiding of Hypersound Underneath a Nanocorrugated Surface.

In nanoscale communications, high-frequency surface acoustic waves are becoming effective data carriers and encoders. On-chip communications require acoustic wave propagation along nanocorrugated surfaces which strongly scatter traditional Rayleigh waves. Here, we propose the delivery of information using subsurface acoustic waves with hypersound frequencies of ∼20 GHz, which is a nanoscale analogue of subsurface sound waves in the ocean.

Resonant thermal energy transfer to magnons in a ferromagnetic nanolayer.

Energy harvesting is a concept which makes dissipated heat useful by transferring thermal energy to other excitations. Most of the existing principles are realized in systems which are heated continuously. We present the concept of high-frequency energy harvesting where the dissipated heat in a sample excites resonant magnons in a thin ferromagnetic metal layer.