We observe the capture and field ionization of individual atoms near the side
wall of a single suspended nanotube. Extremely large cross sections for
ionization from an atomic beam are observed at modest voltages due to the
nanotube's small radius and extended length. The effects of the field strength
on both the atomic capture and the ionization process are clearly distinguished
in the data, as are prompt and delayed ionizations related to the locations at
which they occur. Efficient and sensitive neutral atom detectors can be based
on the nanotube capture and wall ionization processes.Comment: Article (8 pages) and Supplementary Information (4 pages). Associated
figure appeared on cover of the April 2, 2010 issue of PRL
