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Attosecond physics at nanoscale metal tips - strong field physics in the near-field optics regime (NEARFIELDATTO)
Date du début: 1 avr. 2014, Date de fin: 31 mars 2019 PROJET  TERMINÉ 

Electron dynamics in metals and nanostructures take place on attosecond timescales. Until today, these extremely fast processes are little understood let alone utilized. With NearFieldAtto, strong-field driven phenomena at nanoscale metal structures will be explored to elucidate collective electron dynamics and to induce optical-field-driven currents -- on attosecond timescales. We will investigate the near-field of a nanotip, resulting from the collective dynamics, both in amplitude and phase. Conversely, we will use the tip as a nanometric sensor to map out the electric field inside the focus of a pulsed laser beam and will directly measure the local phase. In two-tip and molecular junctions, we will explore the ultrafast steering of electronic currents by optical fields, both over a nanometric gap and inside a molecule, taking advantage of the large near-field enhancement the systems offer.My group has recently shown that attosecond physics phenomena can be observed at solids, namely at nanoscale tips [Krüger et al., Nature 2011]. Hence, in NearFieldAtto we will employ techniques well known from attosecond physics with isolated objects, like gas-phase atoms and molecules, to steer laser-emitted electrons with the electric field of few-cycle laser pulses. We will use these electrons as nanometric probes to investigate optical properties of the solid state system and compare the results with those of isolated objects in gas-phase measurements. With two tips facing each other, we will realize a nanometric junction over which we will steer electrons with the optical field. A molecule placed between two tips will enable the investigation of a novel, ultrafast switching mechanism.NearFieldAtto will bring attosecond physics a leap forward as compared to the state-of-the-art, will introduce strong-field physics into (quantum-)plasmonics, and will open the door towards lightwave or petahertz nano-electronics in metallic and molecular nano-systems.