Generation and Control of Coherent Terahertz Phonons in Silicon Metasurfaces

Abstract

Semiconductor nanostructures are used in many applications, from electronics to nanophotonics to cite just a few, and most of these applications are based on silicon or silicon-related technologies. With the miniaturization of these nanoscale devices, heat dissipation becomes a limitation to their efficiency, robustness, and reliability. Hence, managing thermal effects at nanoscale is attracting a growing interest and a promising approach relies on the control of acoustic phonons that are responsible of heat transfers. However, these phonons in silicon have high frequencies in the terahertz range which makes them hard to control and detect, thus limiting basic investigation and practical implementations. In this work, employing coherent control of femtosecond laser pulses and inelastic scattering spectroscopy, it is reported on the coherent generation, the control, and the detection of acoustic phonons in silicon metasurfaces in which light–matter interactions are enhanced.