Creation and Annihilation of Magnetic Skyrmions for Neuromorphic Computing Applications

In this work we present the creation, annihilation and dynamics of a topologically protected magnetic structure, a skyrmion, for neuromorphic computing application. We study the effect of Dzyaloshinskii Moriya interaction (DMI) and surface anisotropy on the skyrmion density. The relation between skyrmion annihilation threshold anisotropy Kth and DMI coefficient is evaluated. Furthermore, the skyrmion diameter dependence on these two parameters is studied. Using MOKE analysis we study the effect of external magnetic field on the skyrmion density and predict the threshold magnetic field for the transition of magnetic texture from Labriynth domains to skyrmions. These results are further supported by the MuMax simulations. The spin orbit torque SOT manipulation of skyrmion size and density is also presented for skyrmion applications in the race-track memory and neuromorphic computing. Motivated by the results, we propose a Skyrmionic neuromorphic device and using SOT switching mechanism, show its applicability as spintronic synapse and neuron. The MuMax simulations are coupled to the Non- Equilibrium Green’s Function formalism to model the neuron and synapse behavior. Finally, we conclude with the possibility of using these devices for pattern recognition and other unconventional computing paradigms.

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Generation of magnetic skyrmions through pinning effect

Modern Physics Letters B ◽

10.1142/s0217984919500404 ◽

2019 ◽

Vol 33 (02) ◽

pp. 1950040 ◽

Cited By ~ 1

Author(s):

Ji-Chong Yang ◽

Qing-Qing Mao ◽

Yu Shi

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Magnetic Anisotropy ◽

Interaction Strength ◽

Lattice Simulation ◽

Pinning Effect ◽

Ferromagnetic Exchange ◽

Analytical Estimation ◽

Magnetic Skyrmions ◽

Moriya Interaction

Based on analytical estimation and lattice simulation, a proposal is made that magnetic skyrmions can be generated through the pinning effect in 2D chiral magnetic materials, in the absence of an external magnetic field or magnetic anisotropy. In our simulation, stable magnetic skyrmions can be generated in the pinning areas. The properties of the skyrmions are studied for various values of ferromagnetic exchange strength and the Dzyaloshinskii–Moriya interaction strength.

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Computer Simulation of Magnetic Skyrmions

Proceedings ◽

10.3390/ecea-5-06678 ◽

2019 ◽

Vol 46 (1) ◽

pp. 6

Author(s):

Vitalii Kapitan ◽

Egor Vasiliev ◽

Alexander Perzhu

Keyword(s):

Magnetic Field ◽

Numerical Simulation ◽

Computer Simulation ◽

External Magnetic Field ◽

Single Layer ◽

Metropolis Algorithm ◽

Square Lattice ◽

Temperature Behaviour ◽

Magnetic Skyrmions ◽

Moriya Interaction

In this paper, we present the results of a numerical simulation of thermodynamics for the array of Classical Heisenberg spins placed on a 2D square lattice, which effectively represents the behaviour of a single layer. Using the Metropolis algorithm, we show the temperature behaviour of the system with a competing Heisenberg and Dzyaloshinskii–Moriya interaction (DMI) in contrast with the classical Heisenberg system. We show the process of nucleation of the skyrmion depending on the value of the external magnetic field. We proposed the controlling method for the movement of skyrmions.

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Monte Carlo Simulation of Magnetic Skyrmions in Ferromagnetic Films

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.312.256 ◽

2020 ◽

Vol 312 ◽

pp. 256-260

Author(s):

Alexander Perzhu ◽

Egor Vasiliev ◽

Dmitrii Kapitan ◽

Roman Volotovskiy ◽

Alexey Rybin ◽

...

Keyword(s):

Magnetic Field ◽

Monte Carlo Simulation ◽

Monte Carlo ◽

External Magnetic Field ◽

Magnetic Films ◽

Magnetic Vortex ◽

Heisenberg Spin ◽

Monte Carlo Simulation Technique ◽

Magnetic Skyrmions ◽

Moriya Interaction

Magnetic films, in which magnetic vortex textures - skyrmions appear because of competition between the direct Heisenberg exchange and the Dzyaloshinskii-Moriya interaction, were studied using the Monte-Carlo simulation technique. The conditions for the nucleation and stable existence of magnetic skyrmions in magnetic films in the frame of the classical Heisenberg model were considered in the paper. The process of nucleation of skyrmions with increasing of the external magnetic field was studied, various phases into which the Heisenberg spin system passes were recognized. A phase diagram was plotted: it shows the behavior of the system at the constant value of temperature depending on values of an external magnetic field and Dzyaloshinskii-Moriya interaction.

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Superconductors with spin–orbit interactions

International Journal of Modern Physics B ◽

10.1142/s0217979216501836 ◽

2016 ◽

Vol 30 (25) ◽

pp. 1650183 ◽

Cited By ~ 4

Author(s):

Yu. N. Ovchinnikov

Keyword(s):

Magnetic Field ◽

Superconducting Films ◽

Critical Magnetic Field ◽

Spin Orbit ◽

Zero Temperature ◽

Interband Pairing ◽

Two Parameters ◽

Spin Orbit Interactions ◽

Parameter Values ◽

Thin Superconducting Films

The effect of spin-orbit (SO) interaction on the formation of the critical states in thin superconducting films in magnetic field oriented along the film is investigated. Hereby, the case of interband pairing is considered. It was found that eight branches exist in the plane of two parameters [Formula: see text] determined by the value of magnetic field and SO interaction. Six modes leads to inhomogeneous states with different values of the impulse [Formula: see text]. Each state is doubly degenerate over direction of impulse [Formula: see text]. The parameter values at critical point are found for all eight branches in explicit form for zero temperature. The optimal two branches are estimated, corresponding to largest critical magnetic field value for given SO interaction.

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Giant Dzyaloshinskii-Moriya interaction in Rashba superlattices

10.21203/rs.3.rs-39851/v1 ◽

2020 ◽

Author(s):

Woo-Seung Ham ◽

Abdul-Muizz Pradipto ◽

Kay Yakushiji ◽

Kwangsu Kim ◽

Sonny Rhim ◽

...

Keyword(s):

Heavy Metal ◽

Material Design ◽

Orbit Coupling ◽

Inversion Symmetry ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Band Formation ◽

Stacking Order ◽

Magnetic Skyrmions ◽

Moriya Interaction

Abstract Dzyaloshinskii-Moriya interaction (DMI) is considered as one of the most important energy for specific chiral texture such as magnetic skyrmions. The key of generating DMI is absence of structural inversion symmetry and exchange energy with spin-orbit coupling. Therefore, a vast majority of researches about DMI is mainly limited to heavy metal/ferromagnet bilayer systems, only focusing on their interfaces. Here, we report that asymmetric band formation in an artificial superlattice arises from inversion symmetry breaking in stacking order of atomic layers, resulting in bulk DMI. Such bulk DMI is more than 300% larger than simple sum of interfacial contribution. Moreover, the asymmetric band is largely affected by strong spin-orbit coupling, showing crucial role of a heavy metal even in the non-interfacial origin of DMI. Such Rashba superlattices can be a new class of material design for spintronics applications.

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Role of the Fermi-Surface Anisotropy in Angle-Dependent Magnetic-Field Oscillations for Identifying the Energy-Gap Anisotropy ofAyFe2Se2Superconductors

Physical Review Letters ◽

10.1103/physrevlett.109.187006 ◽

2012 ◽

Vol 109 (18) ◽

Cited By ~ 6

Author(s):

Tanmoy Das ◽

Anton B. Vorontsov ◽

Ilya Vekhter ◽

Matthias J. Graf

Keyword(s):

Magnetic Field ◽

Fermi Surface ◽

Energy Gap ◽

Surface Anisotropy ◽

Gap Anisotropy ◽

Fermi Surface Anisotropy

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Entanglement Dynamics of a Two-qubit XYZ Spin Chain Under both Dzyaloshinskii-Moriya Interaction and Time-dependent Anisotropic Magnetic Field

International Journal of Theoretical Physics ◽

10.1007/s10773-020-04502-4 ◽

2020 ◽

Author(s):

Tchoffo Martin ◽

Tene Alain Giresse

Keyword(s):

Magnetic Field ◽

Spin Chain ◽

Time Dependent ◽

Entanglement Dynamics ◽

Moriya Interaction

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QUANTUM COMMUNICATION VIA HEISENBERG XYZ SYSTEM

International Journal of Quantum Information ◽

10.1142/s0219749913500354 ◽

2013 ◽

Vol 11 (03) ◽

pp. 1350035 ◽

Cited By ~ 1

Author(s):

A. EL ALLATI ◽

Y. HASSOUNI ◽

N. METWALLY

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Quantum Communication ◽

Average Fidelity ◽

The Magnetic Field ◽

Moriya Interaction ◽

Degree Of Entanglement

The possibility of generating entangled network via Dzyaloshinskii–Moriya interaction is investigated. The entanglement between the different nodes is quantified. This entangled network is employed to send information between different users who are members on this network. The effect of the field strength and the magnetic field parameters on the degree of entanglement of the network and the average fidelity is discussed. We show that by controlling these parameters one can maximize the average fidelity of the teleported state.

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Quantum teleportation via two-qubit Heisenberg XYZ chain

Canadian Journal of Physics ◽

10.1139/cjp-2013-0404 ◽

2014 ◽

Vol 92 (5) ◽

pp. 406-410 ◽

Cited By ~ 4

Author(s):

Nour Zidan

Keyword(s):

Magnetic Field ◽

External Magnetic Field ◽

Quantum Teleportation ◽

Initial System ◽

Entangled State ◽

Initial State ◽

Intrinsic Decoherence ◽

Average Fidelity ◽

Moriya Interaction

Quantum teleportation via the entanglement channel composed of a two-qubit Heisenberg XYZ chain with Dzyaloshinskii–Moriya interaction in the presence of both inhomogeneous external magnetic field and intrinsic decoherence has been investigated. It is shown that the initial state of the channel plays an important role in the fully entangled fraction and the average fidelity of teleportation. It is found that when the initial system is in the entangled state |Ψ⟩ = m2|01⟩ + n2|10⟩ the corresponding average fidelity is always larger than 2/3.

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