title: Laser-driven nanoplasmas in doped helium droplets: local ignition and anisotropic growth.
abstract: Doping a helium nanodroplet with only a tiny xenon cluster of a few atoms sparks complete ionization of the droplet at laser intensities below the ionization threshold of helium atoms. As a result, the intrinsically inert and transparent droplet turns into a fast and strong absorber of infrared light. Microscopic calculations reveal a two-step mechanism to be responsible for the dramatic change: Avalanchelike ionization of the helium atoms on a femtosecond time scale, driven by field ionization due to the quickly charged xenon core, is followed by resonant absorption enabled by an unusual cigar-shaped nanoplasma within the droplet.
authors.affiliation: Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany.
authors.forename: Alexey
authors.initials: A
authors.lastname: Mikaberidze
authors.forename: Ulf
authors.initials: U
authors.lastname: Saalmann
authors.forename: Jan M
authors.initials: JM
authors.lastname: Rost