title: Magnetic Radial Vortex Stabilization and Efficient Manipulation Driven by the Dzyaloshinskii-Moriya Interaction and Spin-Transfer Torque.
abstract: Solitons are very promising for the design of the next generation of ultralow power devices for storage and computation. The key ingredient to achieving this goal is the fundamental understanding of their stabilization and manipulation. Here, we show how the interfacial Dzyaloshinskii-Moriya Interaction (IDMI) is able to lift the energy degeneracy of a magnetic vortex state by stabilizing a topological soliton with radial chirality, hereafter called radial vortex. It has a noninteger Skyrmion number S (0.5<|S|<1) due to both the vortex core polarity and the magnetization tilting induced by the IDMI boundary conditions. Micromagnetic simulations predict that a magnetoresistive memory based on the radial vortex state in both free and polarizer layers can be efficiently switched by a threshold current density smaller than 10^{6}  A/cm^{2}. The switching processes occur via the nucleation of topologically connected vortices and vortex-antivortex pairs, followed by spin-wave emissions due to vortex-antivortex annihilations.
authors: Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, I-98166 Messina, Italy.
authors: G
authors: G
authors: Siracusano
authors: Department of Engineering, Polo Scientifico Didattico di Terni, University of Perugia, I-50100 Terni, Italy.
authors: R
authors: R
authors: Tomasello
authors: Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, I-98166 Messina, Italy.
authors: A
authors: A
authors: Giordano
authors: Department of Engineering, University of Messina, I-98166 Messina, Italy.
authors: V
authors: V
authors: Puliafito
authors: Department of Engineering, University of Messina, I-98166 Messina, Italy.
authors: B
authors: B
authors: Azzerboni
authors: Department of Physics, Bogazici University, 34342 Bebek/Istanbul, Turkey.
authors: O
authors: O
authors: Ozatay
authors: Department of Electrical and Information Engineering, Politecnico di Bari, via E. Orabona 4, I-70125 Bari, Italy.
authors: M
authors: M
authors: Carpentieri
authors: Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, I-98166 Messina, Italy.
authors: G
authors: G
authors: Finocchio