English
Related papers

Related papers: Thermal vortex dynamics in thin circular ferromagn…

200 papers

Magnetic vortex cores exhibit a gyrotropic motion, and may reach a critical velocity, at which point they invert their z-component of the magnetization. We performed micromagnetic simulations to describe this vortex core polarity reversal…

Mesoscale and Nanoscale Physics · Physics 2016-03-23 G. B. M. Fior , E. R. P. Novais , J. P. Sinnecker , A. P. Guimarães , F. Garcia

We present a quantum mechanical treatment of the mechanical stirring of Bose-Einstein condensates using classical field techniques. In our approach the condensate and excited modes are described using a Hamiltonian classical field method in…

Other Condensed Matter · Physics 2008-12-03 T. M. Wright , R. J. Ballagh , A. S. Bradley , P. B. Blakie , C. W. Gardiner

We study the fluctuation-electromagnetic interaction and dynamics of a small spinning polarizable particle moving with a relativistic velocity in a vacuum background of arbitrary temperature. Using the standard formalism of the fluctuation…

Mesoscale and Nanoscale Physics · Physics 2018-03-02 G. V. Dedkov , A. A. Kyasov

We introduce a new method of statistical analysis to characterise the dynamics of turbulent fluids in two dimensions. We establish that, in equilibrium, the vortex distributions can be uniquely connected to the temperature of the vortex…

We report a time resolved imaging and micromagnetic simulation study of the relaxation dynamics of a magnetic vortex in the non-linear regime. We use time-resolved photoemission electron microscopy and micromagnetic calculations to examine…

Materials Science · Physics 2015-05-13 X. M. Cheng , K. Buchanan , R. Divan , K. Y. Guslienko , D. J. Keavney

We consider the general Landau-Lifshitz-Gilbert (LLG) dynamical theory underlying the magnetization switching rates of a thin film uniaxial magnet subject to spin-torque effects and thermal fluctuations (thermal noise). After discussing the…

Mesoscale and Nanoscale Physics · Physics 2013-08-01 D. Pinna , A. D. Kent , D. L. Stein

We study the rotational motion of nano-flake ferromagnetic discs suspended in a Newtonian fluid, as a potential material owing the vortex-like magnetic configuration. Using analytical expressions for hydrodynamic, magnetic and Brownian…

We study the magnetization dynamics in a nanocontact magnetic vortex oscillators as function of temperature. Low temperature experiments reveal that the dynamics at low and high currents differ qualitatively. At low currents, we excite a…

Through the Ginzburg-Landau and the Navier-Stokes equations, we study turbulence phenomena for viscous incompressible and compressible fluids by a second order phase transition. For this model, the velocity is defined by the sum of…

Fluid Dynamics · Physics 2019-12-30 Mauro Fabrizio

Below the Curie temperature T_c of a Heusler-alloy film, consisting of densely packed, but exchange-decoupled nanograins, the spontaneous magnetization M_s(T) and static in-plane susceptibility \chi_{||}(T) increase very slowly signalizing…

Other Condensed Matter · Physics 2009-11-11 Jürgen Kötzler , Detlef Görlitz , Malte Kurfiß , Lars von Sawilski , Elena Y. Vedmedenko

The effect of thermal fluctuations on a thin film magnetoresistive element has been calculated. The technique involves adding to the basic spin dynamics a general form of interaction with a thermal bath. For a general anisotropic magnetic…

Materials Science · Physics 2007-05-23 Vladimir L. Safonov , H. Neal Bertram

We report magneto-transport measurements on a superconducting molybdenum-germanium (MoGe) film of thickness $d$=50 nm in parallel magnetic fields and show evidence of a transition from a Meissner state to a resistive state of spontaneous…

Superconductivity · Physics 2015-10-21 Milind N. Kunchur , Manlai Liang , Alex Gurevich

Thermal fluctuations of nanomagnets driven by spin-polarized currents are treated via the Landau-Lifshitz-Gilbert equation as generalized to include both the random thermal noise field and Slonczewski spin-transfer torque terms. The…

Statistical Mechanics · Physics 2017-09-26 Y. P. Kalmykov , D. Byrne , W. T. Coffey , W. J. Dowling , S. V. Titov , J. E. Wegrowe

The dynamics of vortices in a 2D Heisenberg antiferromagnet with an easy-plane anisotropy is studied numerically within the discrete spin model as well as analytically within a continuum approximation based on a suitable extension of the…

Strongly Correlated Electrons · Physics 2009-10-28 S. Komineas , N. Papanicolaou

Understanding the dynamics of magnetic vortices has emerged as an important challenge regarding the recent development of spin-torque vortex oscillators. Either micromagnetic simulations or the analytical Thiele equation approach are…

Mesoscale and Nanoscale Physics · Physics 2023-11-23 Simon De Wergifosse , Chloé Chopin , Flavio Abreu Araujo

We found from analytical derivations and micromagnetic numerical simulations that there exist two distinct normal modes in apparently complex vortex gyrotropic motions in two dipolar-coupled magnetic nanodisks. The normal modes have…

Materials Science · Physics 2015-05-27 Ki-Suk Lee , Hyunsung Jung , Dong-Soo Han , Sang-Koog Kim

The study of vortex dynamics using a variational formulation has an extensive history and a rich literature. The standard Hamiltonian function that describes the dynamics of interacting point vortices of constant strength is the…

Fluid Dynamics · Physics 2023-03-20 Nabil M. Khalifa , Haithem E. Taha

The magnetic vortex core in a nanodot can be switched by an alternating transversal magnetic field. We propose a simple collective coordinate model which describes comprehensive vortex core dynamics, including resonant behavior, weakly…

Mesoscale and Nanoscale Physics · Physics 2020-07-23 Oleksandr V. Pylypovskyi , Denis D. Sheka , Volodymyr P. Kravchuk , Yuri Gaididei , Franz G. Mertens

Steady-state turbulent motion is created in superfluid 3He-B at low temperatures in the form of a turbulent vortex front, which moves axially along a rotating cylindrical container of 3He-B and replaces vortex-free flow with vortex lines at…

Other Condensed Matter · Physics 2013-05-29 J. J. Hosio , V. B. Eltsov , R. de Graaf , P. J. Heikkinen , R. Hanninen , M. Krusius , V. S. L'vov , G. E. Volovik

The stable vortex state that occurs in micron-scale magnetic disks is one of the most interesting and potentially useful phenomenon in nanomagnetism. A variety of tools have been applied to study the vortex state, and collective spin…

Mesoscale and Nanoscale Physics · Physics 2020-07-07 P. H. Kim , F. Fani Sani , M. R. Freeman , J. P. Davis