title: Multidimensional instability and dynamics of spin avalanches in crystals of nanomagnets.
abstract: We obtain a fundamental instability of the magnetization-switching fronts in superparamagnetic and ferromagnetic materials such as crystals of nanomagnets, ferromagnetic nanowires, and systems of quantum dots with large spin. We develop the instability theory for both linear and nonlinear stages. By using numerical simulations we investigate the instability properties focusing on spin avalanches in crystals of nanomagnets. The instability distorts spontaneously the fronts and leads to a complex multidimensional front dynamics. We show that the instability has a universal physical nature, with a deep relationship to a wide variety of physical systems, such as the Darrieus-Landau instability of deflagration fronts in combustion, inertial confinement fusion, and thermonuclear supernovae, and the instability of doping fronts in organic semiconductors.
authors.affiliation: Department of Physics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Jukimenko
authors.affiliation: Department of Physics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: C M
authors.initials: CM
authors.lastname: Dion
authors.affiliation: Department of Physics, Umeå University, SE-901 87 Umeå, Sweden and Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Marklund
authors.affiliation: Department of Physics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: V
authors.initials: V
authors.lastname: Bychkov