title: Wake-Mediated Propulsion of an Upstream Particle in Two-Dimensional Plasma Crystals.
abstract: The wake-mediated propulsion of an "extra" particle in a channel of two neighboring rows of a two-dimensional plasma crystal, observed experimentally by Du et al. [Phys. Rev. E 89, 021101(R) (2014)PRESCM1539-375510.1103/PhysRevE.89.021101], is explained in simulations and theory. We use the simple model of a pointlike ion wake charge to reproduce this intriguing effect in simulations, allowing for a detailed investigation and a deeper understanding of the underlying dynamics. We show that the nonreciprocity of the particle interaction, owing to the wake charges, is responsible for a broken symmetry of the channel that enables a persistent self-propelled motion of the extra particle. We find good agreement of the terminal extra-particle velocity with our theoretical considerations and with experiments.
authors.affiliation: Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Weßling, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Laut
authors.affiliation: Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Weßling, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Räth
authors.affiliation: Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Weßling, Germany.
authors.forename: S K
authors.initials: SK
authors.lastname: Zhdanov
authors.affiliation: Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Weßling, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Nosenko
authors.affiliation: Max Planck Institute for Extraterrestrial Physics, 85741 Garching, Germany.|BMSTU Centre for Plasma Science and Technology, Moscow 105005, Russia.
authors.forename: G E
authors.initials: GE
authors.lastname: Morfill
authors.affiliation: Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), 82234 Weßling, Germany.
authors.forename: H M
authors.initials: HM
authors.lastname: Thomas