scholarly journals The Bloch point 3D topological charge induced by the magnetostatic interaction

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
F. Tejo ◽  
R. Hernández Heredero ◽  
O. Chubykalo-Fesenko ◽  
K. Y. Guslienko
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Topological Charge ◽  
Topological Defect ◽  
Energy Contribution ◽  
Magnetostatic Interaction ◽  
New Class ◽  
Magnetostatic Energy ◽  
Topological Hall Effect ◽  
The Bloch Point

AbstractA hedgehog or Bloch point is a point-like 3D magnetization configuration in a ferromagnet. Regardless of widely spread treatment of a Bloch point as a topological defect, its 3D topological charge has never been calculated. Here, applying the concepts of the emergent magnetic field and Dirac string, we calculate the 3D topological charge (Hopf index) of a Bloch point and show that due to the magnetostatic energy contribution it has a finite, non-integer value. Thus, Bloch points form a new class of hopfions—3D topological magnetization configurations. The calculated Bloch point non-zero gyrovector leads to important dynamical consequences such as the appearance of topological Hall effect.

scholarly journals Topological Hall effect for electron scattering on nanoscale skyrmions in external magnetic field

2018 ◽  
Vol 98 (21) ◽  
Author(s):  
K. S. Denisov ◽  
I. V. Rozhansky ◽  
M. N. Potkina ◽  
I. S. Lobanov ◽  
E. Lähderanta ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Hall Effect ◽  
Electron Scattering ◽  
Topological Hall Effect

Topological Hall Effect of Spin-2 Condensate in a Time and Space-Dependent Magnetic Field

2016 ◽  
Vol 55 (11) ◽  
pp. 4633-4640
Author(s):  
Gong-Ping Zheng ◽  
Zhe Wu ◽  
Gao-Zhan Chang ◽  
Ling-Ling Yang
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Time And Space ◽  
Topological Hall Effect

Design, Fabrication and Characterization of a New Magnetic Microsensor Using Plasma Hall Effect

2000 ◽  
Author(s):  
Young Ho Seo ◽  
Ki-Ho Han ◽  
Young-Ho Cho
Keyword(s):  
Magnetic Field ◽  
Theoretical Analysis ◽  
Hall Effect ◽  
Plasma Discharge ◽  
Discharge Voltage ◽  
Chamber Pressure ◽  
Hall Voltage ◽  
New Class ◽  
Discharge Field

Abstract This paper is the first attempt to use the plasma Hall effect for magnetic field detection. The plasma Hall microsensor measures the Hall voltage induced by AC plasma electrons. In a theoretical analysis, we develop an analytical model of the plasma Hall sensor in order to express the plasma Hall voltage as a function of electrode geometry, magnetic field, plasma discharge field and chamber pressure. On this basis, we have designed and fabricated a new class of magnetic microsensors using AC neon plasma. In the experimental study, we have measured the plasma Hall voltage for varying five different conditions, including the frequency and magnitude of magnetic field, the frequency and magnitude of plasma discharge voltage, and the neon pressure. The plasma Hall microsensors show a magnetic field sensitivity of 8.87±0.18mvV/G with 4.48% nonlinearity. The experimental results agree well with those estimated from the theoretical analysis, thus verifying the feasibility of the plasma Hall device for a new class of magnetic microsensor.

scholarly journals Visualizing the strongly reshaped skyrmion Hall effect in multilayer wire devices

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anthony K. C. Tan ◽  
Pin Ho ◽  
James Lourembam ◽  
Lisen Huang ◽  
Hang Khume Tan ◽  
...  
Keyword(s):  
Hall Effect ◽  
Topological Charge ◽  
Size Dependence ◽  
Particle Model ◽  
Model Simulations ◽  
Generation Computing ◽  
Magnetic Skyrmions ◽  
Transverse Deflection ◽  
Robust Framework ◽  
Geometric Effects

AbstractMagnetic skyrmions are nanoscale spin textures touted as next-generation computing elements. When subjected to lateral currents, skyrmions move at considerable speeds. Their topological charge results in an additional transverse deflection known as the skyrmion Hall effect (SkHE). While promising, their dynamic phenomenology with current, skyrmion size, geometric effects and disorder remain to be established. Here we report on the ensemble dynamics of individual skyrmions forming dense arrays in Pt/Co/MgO wires by examining over 20,000 instances of motion across currents and fields. The skyrmion speed reaches 24 m/s in the plastic flow regime and is surprisingly robust to positional and size variations. Meanwhile, the SkHE saturates at ∼22∘, is substantially reshaped by the wire edge, and crucially increases weakly with skyrmion size. Particle model simulations suggest that the SkHE size dependence — contrary to analytical predictions — arises from the interplay of intrinsic and pinning-driven effects. These results establish a robust framework to harness SkHE and achieve high-throughput skyrmion motion in wire devices.

Topological Hall effect in frustrated B2-ordered Mn0.74Co0.57Al0.69 films

2021 ◽  
Vol 104 (6) ◽  
Author(s):  
Peng Chen ◽  
Chunlei Zhang ◽  
Yongzuo Wang ◽  
Bing Lv ◽  
Pei Liu ◽  
...  
Keyword(s):  
Hall Effect ◽  
Topological Hall Effect

scholarly journals The quantum Hall effect in the absence of disorder

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Kyung-Su Kim ◽  
Steven A. Kivelson
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Quantum Hall Effect ◽  
Finite Interval ◽  
Quantum Hall ◽  
Wigner Crystal ◽  
Quasi Particle ◽  
Hall Conductance ◽  
Finite Extent

AbstractIt is widely held that disorder is essential to the existence of a finite interval of magnetic field in which the Hall conductance is quantized, i.e., for the existence of “plateaus” in the quantum Hall effect. Here, we show that the existence of a quasi-particle Wigner crystal (QPWC) results in the persistence of plateaus of finite extent even in the limit of vanishing disorder. Several experimentally detectable features that characterize the behavior in the zero disorder limit are also explored.

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