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Related papers: Twisted Magnetic Knots and Links

200 papers

Current-induced magnetic switching of a single magnetic molecule attached to two ferromagnetic contacts is considered theoretically, with the main emphasis put on the role of intrinsic spin relaxation processes. It is shown that…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Maciej Misiorny , Józef Barnaś

Dynamos wherein magnetic field is produced from velocity fluctuations are fundamental to our understanding of several astrophysical and/or laboratory phenomena. Though fluid helicity is known to play a key role in the onset of dynamo…

Plasma Physics · Physics 2023-07-05 Shishir Biswas , Rajaraman Ganesh

To give a general description of the influences of electric fields or currents on magnetization dynamics, we developed a semiclassical theory for the magnetization implicitly coupled to electronic degrees of freedom. In the absence of…

Mesoscale and Nanoscale Physics · Physics 2018-07-25 Bangguo Xiong , Hua Chen , Xiao Li , Qian Niu

Using a full kinetic, implicit particle-in-cell code, iPiC3D, we studied the properties of plasma kinetic turbulence, such as would be found at the interface between the solar wind and the Earth magnetosphere at low latitude during…

Plasma Physics · Physics 2014-12-04 Koen Kemel , Pierre Henri , Giovanni Lapenta , Francesco Califano , Stefano Markidis

The theory of large scale dynamos is reviewed with particular emphasis on the magnetic helicity constraint in the presence of closed and open boundaries. In the presence of closed or periodic boundaries, helical dynamos respond to the…

Astrophysics · Physics 2009-11-07 A. Brandenburg , W. Dobler , K. Subramanian

Flat magnetic nano-elements are an essential component of current and future spintronic devices. By shaping an element it is possible to select and stabilize chosen metastable magnetic states, control its magnetization dynamics. Here, using…

Mesoscale and Nanoscale Physics · Physics 2015-08-24 Andrei B. Bogatyrev , Konstantin L. Metlov

High-resolution X-ray observations have revealed cavities and `cold fronts' with sharp edges in temperature, density, and metallicity within galaxy clusters. Their presence poses a puzzle since these features are not expected to be…

Astrophysics · Physics 2009-11-13 L. J. Dursi , C. Pfrommer

Magnetic clouds (MCs) are large-scale interplanetary transient structures in the heliosphere that travel from the Sun into the interplanetary medium. The internal magnetic field lines inside the MCs are twisted, forming a flux rope (FR).…

Space Physics · Physics 2020-03-11 V. Lanabere , S. Dasso , P. Démoulin , M. Janvier , L. Rodriguez , J. J. Masías-Meza

We develop an effective field theory approach to inspect the electromagnetic interactions in an electrically neutral plasma, with an equal number of negative and positive charge carriers. We argue that the static equilibrium configurations…

Plasma Physics · Physics 2009-11-06 Ludvig Faddeev , Antti J. Niemi

Stable three-dimensional topological skyrmion structures in frustrated magnets are investigated. The texture exhibits a helicoid pattern along the vertical direction, described by a position-dependent helicity, which interpolates between…

Mesoscale and Nanoscale Physics · Physics 2025-12-01 Carlos Saji , Eduardo Saavedra , Vagson L. Carvalho-Santos , Alvaro S. Nunez , Roberto E. Troncoso

We briefly review helicity dynamics, inverse and bi-directional cascades in fluid and magnetohydrodynamic (MHD) turbulence, with an emphasis on the latter. The energy of a turbulent system, an invariant in the non-dissipative case, is…

Fluid Dynamics · Physics 2019-03-13 A. Pouquet , D. Rosenberg , J. E. Stawarz , R. Marino

We construct a magnetic helicity conserving dynamo theory which incorporates a calculated magnetic helicity current. In this model the fluid helicity plays a small role in large scale magnetic field generation. Instead, the dynamo process…

Astrophysics · Physics 2009-10-31 Ethan T. Vishniac , Jungyeon Cho

Helically coiled filaments are a frequent motif in nature. In situations commonly encountered in experiments coiled helices are squeezed flat onto two dimensional surfaces. Under such 2-D confinement helices form "squeelices" - peculiar…

Soft Condensed Matter · Physics 2015-06-05 Gi-Moon Nam , Nam-Kyung Lee , Hervé Mohrbach , Albert Johner , Igor M. Kulić

Dynamo processes are ubiquitous in astrophysical systems. In relativistic astrophysical systems, such as accretion disks around black holes or neutron stars, they may critically affect the launching of winds and jets that can power…

High Energy Astrophysical Phenomena · Physics 2025-07-31 Jiaxi Wu , Elias R. Most

Rotating magnetic structures are common in astrophysics, from vortex tubes and tornados in the Sun all the way to jets in different astrophysical systems. The physics of these objects often combine inertial, magnetic, gas pressure and…

Solar and Stellar Astrophysics · Physics 2018-08-29 Manuel Luna , Eric Priest , Fernando Moreno-Insertis

We investigate nonequilibrium phenomena in magnetic nano-junctions using a numerical approach that combines classical spin dynamics with the hierarchical equations of motion technique for quantum dynamics of conduction electrons. Our focus…

Mesoscale and Nanoscale Physics · Physics 2024-02-26 Rudolf Smorka , Michael Thoss , Martin Žonda

Magnetic helicity, $H$, measures magnetic linkages in a volume. The early theoretical development of helicity focused on magnetically closed systems in $\mathcal{V}$ bounded by $\mathcal{S}$. For magnetically closed systems,…

Solar and Stellar Astrophysics · Physics 2023-09-15 Peter W. Schuck , Mark G. Linton

The origin and evolution of the magnetic helicity in the solar corona are not well understood. For instance, the magnetic helicity of an active region is often about $10^{42}$ Mx$^2$ ($10^{26}$ Wb$^{2}$), but the observed processes whereby…

Solar and Stellar Astrophysics · Physics 2009-11-13 S. Regnier

Magnetic winding is a fundamental topological quantity that underpins magnetic helicity and measures the entanglement of magnetic field lines. Like magnetic helicity, magnetic winding is also an invariant of ideal magnetohydrodynamics. In…

Plasma Physics · Physics 2021-03-17 Chris Prior , David MacTaggart

It is shown that the transport in low temperature, collisional, bounded plasma is enhanced by instabilities at high magnetic field. While the magnetic field confines the electrons in a stable plasma, the instability completely destroys the…

Plasma Physics · Physics 2019-09-04 R. Lucken , A. Bourdon , M. Lieberman , P. Chabert