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A previously published analytical magnetohydrodynamic model for the local interstellar magnetic field in the vicinity of the heliopause (R\"oken et al. 2015) is extended from incompressible to compressible, yet predominantly subsonic flow,…

Solar and Stellar Astrophysics · Physics 2017-04-05 J. Kleimann , C. Röken , H. Fichtner

Ferromagnetic matter finds its microscopic origin in the intrinsic electron spin, which is considered to be a purely quantum mechanical property of the electron. To incorporate the influence of the electron spin in the microscopic and…

Classical Physics · Physics 2024-06-11 Bela Schulte Westhoff

A proxy for horizontal electric currents in the solar photosphere was suggested. For a set of evolving active regions (ARs) observed with {\it Solar and Heliospheric Observatory (SOHO)} Michelson Doppler Imager (MDI) in the high resolution…

Astrophysics · Physics 2008-06-11 Valentyna Abramenko

A persistent current, coupled with the spin state, of purely many-body origin is shown to exist in Nagaoka's ferromagnetic state in two dimensions (2D). This we regard as a manifestation of a gauge field, which comes from the surrounding…

Condensed Matter · Physics 2009-10-28 K. Kusakabe , H. Aoki

The neutrals in the Earth environment are in fact free and subjected to drag forces (by ions). In this study we show that drag or friction forces in the ionosphere-thermosphere system initiate changes in the plasma flow, neutral wind, and…

Space Physics · Physics 2014-04-01 Petko Nenovski

Persistent currents flowing through disordered mesoscopic rings threaded by a magnetic flux are investigated. Models of fermions with on-site interactions (Hubbard model) or models of spinless fermions with nearest neighbor interactions are…

Condensed Matter · Physics 2007-05-23 Georges Bouzerar , Didier Poilblanc

The process of current filamentation in permanently externally driven, initially globally ideal plasmas is investigated by means of two-dimensional Magnetohydrodynamic (MHD)-simulations. This situation is typical for astrophysical systems…

Astrophysics · Physics 2009-10-31 C. Konz , H. Wiechen , H. Lesch

The persistent current in small isolated rings enclosing magnetic flux is the current circulating in equilibrium in the absence of an external excitation. While initially studied in superconducting and normal metals, recently, atomic…

Quantum Gases · Physics 2022-03-08 Ovidiu I. Patu , Dmitri V. Averin

The specific role of environmental interaction on bias driven circular current in a ring nanojunction is explored within a tight-binding framework based on wave-guide theory. The environmental interaction is implemented through disorder in…

Mesoscale and Nanoscale Physics · Physics 2025-05-05 Moumita Mondal , Santanu K. Maiti

Spin states and persistent currents are investigated theoretically in a mesoscopic ring with an embedded magnetic ion under a uniform magnetic field including the spin-orbit interactions. The magnetic impurity acts as a spin-dependent…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 J. S. Sheng , Kai Chang

Recently several cases of observations of unipolar magnetic field pulses associated with earthquakes at different points (California, Italy, Peru) have been recorded. The paper attempts to model unipolar magnetic field pulses based on one…

Geophysics · Physics 2018-02-27 Petko Nenovski

We study the long-term quasi-steady evolution of the force-free magnetosphere of a magnetar coupled to its internal magnetic field. We find that magnetospheric currents can be maintained on long timescales of the order of thousands of…

High Energy Astrophysical Phenomena · Physics 2018-10-11 Taner Akgün , Pablo Cerdá-Durán , Juan Antonio Miralles , José A. Pons

The non-collisional interaction between conducting obstacles and magnetized plasma winds can be found in different scenarios, from the interaction occurring between regions inside galaxy clusters to the interaction between the solar wind…

Earth and Planetary Astrophysics · Physics 2015-06-22 Norberto Romanelli , Daniel Gomez , Cesar Bertucci , Magda Delva

Spin-polarized electric current exerts torque on local magnetic spins, resulting in magnetic domain-wall (DW) motion in ferromagnetic nanowires. Such current-driven DW motion opens great opportunities toward next-generation magnetic devices…

We consider electron transport in ferromagnets or antiferromagnets sandwiched between metals. When spins in the magnetic materials precess, they emit currents into the surrounding conductors. Generally, adiabatic pumping in mesoscopic…

Mesoscale and Nanoscale Physics · Physics 2020-08-17 Arne Brataas

The impact of interplanetary shocks on the magnetosphere can trigger magnetic substorms that intensify auroral electrojet currents. These currents enhance ground magnetic field perturbations (d$B$/d$t$), which in turn generate…

We establish a mathematically rigorous, general and quantitative framework to describe currents of non- (or weakly) interacting, indistinguishable particles driven far from equilibrium. We derive tight upper and lower bounds for the…

Quantum Physics · Physics 2017-03-03 Mattia Walschaers , Andreas Buchleitner , Mark Fannes

The present study examines the response of the terrestrial magnetosphere to the long-term steady declining trends observed in solar magnetic fields and solar wind micro-turbulence levels since mid-1990's that has been continuing beyond the…

Solar and Stellar Astrophysics · Physics 2019-08-08 M. Ingale , P. Janardhan , S. K. Bisoi

An equation of motion is derived for a topologically cylindrical worldsheet of lightlike electromagnetic current, embedded in 3+1 dimensions in a smooth external electromagnetic field. Then it is shown that the static circle of uniformly…

Classical Physics · Physics 2012-12-24 J. Margulies

Topological phase space disconnection has been recently found to be a general phenomenon in isolated anisotropic spin systems. It sets a general framework to understand the emergence of ferromagnetism in finite magnetic systems starting…

Statistical Mechanics · Physics 2014-07-29 F. Borgonovi , G. L. Celardo , B. Goncalves , L. Spadafora