Final Report Summary - NEARFIELDATTO (Attosecond physics at nanoscale metal tips - strong field physics in the near-field optics regime)
The ERC grant NearFieldAtto led to a number of new and important results. We have gained new insights into how optical fields interact with nanometer sharp needles. We could show that electrons can be coherently driven inside of the quantum material graphene. In particular, we could show a record-fast turn-on time of a current of 1 fs with the help of the very first observation of strong-field physics inside of a conductor. We could also measure a record-large coherence of free-space laser-triggered electron beams and have built the nanoscale version of a tube-diode based on two nanometer sharp needle tips. We have also used the gained insights into strong-field physics at needle tips to scan the focus of pulsed laser beams and, for the first time, measure the optical phase in full three dimensions, which is important to know for almost any light-matter interaction.