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Related papers: Anti-vortex state in cross-like nanomagnets

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Motivated by recent experiments\cite{BA}\cite{BB}, we study quasi 2D ferromagnetic condensates with various aspect ratios. We find that in zero magnetic field, dipolar energy generates a local energy minimum with all the spins lie in the 2D…

Quantum Gases · Physics 2015-05-13 Jian Zhang , Tin-Lun HO

How stable vortex-like magnetization in magnetic nanodisks with small aspect ratio ($L/R<<1$) is affected by two antidots is investigated analytically and by Monte Carlo simulations. For suitable ranges of the physical parameters this…

Materials Science · Physics 2015-06-25 A. R. Pereira , A. R. Moura , W. A. Moura-Melo , D. F. Carneiro , S. A. Leonel , P. Z. Coura

We report here the results of two-dimensional electron gas based micro-Hall magnetometry measurements and micromagnetic simulations of dipolar coupled nanomagnets of Ni80Fe20 arranged in a double ring-like geometry. We observe that although…

Mesoscale and Nanoscale Physics · Physics 2020-03-12 N. Keswani , Y. Nakajima , N. Chauhan , H. Chakraborti , K. Dasgupta , S. Kumar , Y. Ohno , H. Ohno , P. Das

Magnetic vortices existing in soft magnetic nanoparticles with sizes larger than the single-domain diameter can be efficient nano-heaters in biomedical applications. Using micromagnetic numerical simulation we prove that in the optimal…

Mesoscale and Nanoscale Physics · Physics 2017-09-04 N. A. Usov , M. S. Nesmeyanov , V. P. Tarasov

Ferromagnetic electrodes of a lateral semiconductor-based spin-valve structure are designed to provide a maximum of spin-polarized injection current. A single-domain state in remanence is a prerequisite obtained by nanostructuring Permalloy…

Other Condensed Matter · Physics 2007-05-23 T. Last , S. Hacia , M. Wahle , S. F. Fischer , U. Kunze

In this study, a preparation route of Co-Cu alloys with soft magnetic properties by high-pressure torsion deformation is introduced. Nanocrystalline, supersaturated single-phase microstructures are obtained after deformation of Co-Cu…

We consider magnetic properties of a long, thin-walled ferromagnetic nanotube. We assume that the tube consists of isotropic homogeneous magnet whose spins interact via the exchange energy, the dipole-dipole interaction energy, and also…

Materials Science · Physics 2015-06-17 Chen Sun , Valery L. Pokrovsky

A quasiclassical theory of giant magnetoresistance in nanoscale point contacts between different ferromagnetic metals is developed. The contacts were sorted by three types of mutual positions of the conduction spin-subband bottoms which are…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 A. N. Useinov , R. G. Deminov , L. R. Tagirov , G. Pan

The spin dynamics are calculated for a model system consisting of magnetically soft, layered nanomagnets, in which two ferromagnetic (F) cylindrical dots, each with a magnetic vortex ground state, are separated by a non-magnetic spacer (N).…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 K. Yu. Guslienko , K. S. Buchanan , S. D. Bader , V. Novosad

We report on experimental and computational investigations of the domain structure of ~0.2 x 0.2 x 8 {\mu}m single-crystal Ni nanowires (NWs). The Ni NWs were grown by a thermal chemical vapor deposition technique that results in…

Mesoscale and Nanoscale Physics · Physics 2018-06-27 Jimmy J. Kan , Marko V. Lubarda , Keith T. Chan , Vojtech Uhlir , Andreas Scholl , Vitaliy Lomakin , Eric E. Fullerton

We show that very large negative magnetoresistance can be obtained in magnetic trilayers in a current-in-plane geometry owing to the existence of crossed Andreev reflection. This spin-valve consists of a thin superconducting film sandwiched…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 F. Giazotto , F. Taddei , R. Fazio , F. Beltram

The physics of quantized vortex excitations in atomic Bose-Einstein condensates has been extensively studied in recent years.Although simple vortex lines are relatively easy to create, control, and measure in experiments, it is a lot more…

Quantum Physics · Physics 2020-10-28 James Schloss , Peter Barnett , Rashi Sachdeva , Thomas Busch

Abrikosov vortices, where the superconducting gap is completely suppressed in the core, are dissipative, semi-classical entities that impact applications from high-current-density wires to superconducting quantum devices. In contrast, we…

We report on a study of the dynamics of a magnetic antivortex in a submicron, asteroid shaped, permalloy ferromagnet using micromagnetic simulations. As with vortex states in disk and square geometries, a gyrotropic mode was found in which…

Materials Science · Physics 2007-05-23 Hao Wang , C. E. Campbell

We report magnetoresistance measurements through Nb films having a periodic thickness modulation. The cylinder shaped large-thickness regions of the sample, which form a square lattice, act as repulsive centers for the superconducting…

Superconductivity · Physics 2015-03-20 Jorge I. Facio , Anabella Abate , J. Guimpel , Pablo S. Cornaglia

A phenomenological theory of magnetic states in noncentrosymmetric tetragonal antiferromagnets is developed, which has to include homogeneous and inhomogeneous terms (Lifshitz-invariants) derived from Dzyaloshinskii-Moriya couplings.…

Strongly Correlated Electrons · Physics 2009-11-07 A. N. Bogdanov , U. K. Roessler , M. Wolf , K. -H. Muller

We present a complete theory of the spin torque phenomena in a ultrasmall nanomagnet coupled to non-collinear ferromagnetic electrodes through tunnelling junctions. This model system can be described by a simple microscopic model which…

Mesoscale and Nanoscale Physics · Physics 2008-02-22 O. Parcollet , X. Waintal

In this paper we show spin dependent transport experiments in nanoconstrictions ranging from 30 to 200nm. These nanoconstrictions were fabricated combining electron beam lithography and thin film deposition techniques. Two types of…

We measure electron tunneling via discrete energy levels in ferromagnetic cobalt particles less than 4 nm in diameter, using non-magnetic electrodes. Due to magnetic anisotropy, the energy of each tunneling resonance shifts as an applied…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. Gueron , Mandar M. Deshmukh , E. B. Myers , D. C. Ralph

In a nanomagnet (whose total spin S< 1000), very small polarized currents can lead to magnetic reversal. Treating on the same footing the transport and magnetic properties of a nanomagnet connected to magnetic leads via tunneling barriers,…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 X. Waintal , O. Parcollet
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