  The promise of ultrafast light field driven electronic nanocircuits has
stimulated the development of the new research field of attosecond nanophysics.
An essential prerequisite for advancing this new area is the ability to
characterize optical nearfields from light interaction with nanostructures with
sub cycle resolution. Here, we experimentally demonstrate attosecond nearfield
retrieval with a gold nanotip using streaking spectroscopy. By comparison of
the results from gold nanotips to those obtained for a noble gas, the spectral
response of the nanotip near field arising from laser excitation can be
extracted. Monte Carlo MC trajectory simulations in near fields obtained with
the macroscopic Maxwells equations elucidate the streaking mechanism on the
nanoscale.
