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One of the most fundamental processes in nature is the photoemission of electrons from solid targets. This process forms the basis for optoelectronics, where light can trigger electron transfer, amplification, and emission, and electron injection and excitation can result in the emission of light. The decrease in the dimensions of electronic and optoelectronic circuitry is directly linked to a potential increase in their speed of operation. On nanometer dimensions electrons typically move on attosecond to femtosecond timescales. The inherent link between these spatial and temporal dimensions has recently given rise to the new field of attosecond nanophysics.
The talk will introduce new measurement concepts that permit to obtain information with highest time and spatial resolution. It will be shown, how these have been recently applied to obtain microscopic information about the photoemission of electrons from nanoparticles and nanoantennas using extreme ultraviolet light. The talk will also introduce how strong fields can both lead to photoemission when the workfunction is higher than the photon energy, and how electron emission in such strong fields can be controlled with the electric field waveform of visible light. Finally, the optical properties of nanomaterials, in contrast to their bulk solid counterparts, can heavily depend on their shape and size, which permits tempering with ultrafast optoelectronic properties using these parameters. As an example, it will be shown how the dimensions of nanoparticles strongly influence their near-fields leading to effects such as nanofocusing, which can be exploited to accelerate freed electrons and create bursts of attosecond electron pulses with extremely high energies.
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