Generation and Control of Coherent Terahertz Phonons in Silicon Metasurfaces

摘要

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