Magnetic dipole configurations on honeycomb lattices: effect of finite size and boundaries

Artificial dipolar spin-ice patterns have attracted much attention recently because of their rich configurations and excitations in the form of Dirac strings connecting magnetic monopoles. We have analysed the distribution of excitations in the form of strings and vertices carrying magnetic charges Q =±3 q in honeycomb artificial spin-ice patterns. Two types of patterns are compared, those that terminate with open hexagons and those with closed hexagons. The dipole configurations and the frequency of spin-ice rule-violating Q =±3 q vertices depend slightly on the boundary conditions of the pattern. Upon rotation of the patterns by 2 π in a coercive magnetic field of 500 Oe, complete reversibility of the charge and string configuration is observed.

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Quantitative imaging of the magnetic field distribution in an artificial spin ice studied by off-axis electron holography

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2021.168535 ◽

2021 ◽

pp. 168535

Author(s):

Teresa Weßels ◽

András Kovács ◽

Sebastian Gliga ◽

Simone Finizio ◽

Jan Caron ◽

...

Keyword(s):

Magnetic Field ◽

Field Distribution ◽

Quantitative Imaging ◽

Magnetic Field Distribution ◽

Electron Holography ◽

Spin Ice ◽

Artificial Spin Ice ◽

The Magnetic Field

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Thermally and field-driven mobility of emergent magnetic charges in square artificial spin ice

Scientific Reports ◽

10.1038/s41598-019-52460-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Sophie A. Morley ◽

Jose Maria Porro ◽

Aleš Hrabec ◽

Mark C. Rosamond ◽

Diego Alba Venero ◽

...

Keyword(s):

Critical Field ◽

Magnetic Monopoles ◽

Model Systems ◽

Square Lattice ◽

Creep Model ◽

Spin Ice ◽

One Dimensional ◽

X Ray ◽

Drift Motion ◽

Artificial Spin Ice

Abstract Designing and constructing model systems that embody the statistical mechanics of frustration is now possible using nanotechnology. We have arranged nanomagnets on a two-dimensional square lattice to form an artificial spin ice, and studied its fractional excitations, emergent magnetic monopoles, and how they respond to a driving field using X-ray magnetic microscopy. We observe a regime in which the monopole drift velocity is linear in field above a critical field for the onset of motion. The temperature dependence of the critical field can be described by introducing an interaction term into the Bean-Livingston model of field-assisted barrier hopping. By analogy with electrical charge drift motion, we define and measure a monopole mobility that is larger both for higher temperatures and stronger interactions between nanomagnets. The mobility in this linear regime is described by a creep model of zero-dimensional charges moving within a network of quasi-one-dimensional objects.

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Investigation of the Finite Size Properties of the Ising Model Under Various Boundary Conditions

Zeitschrift für Naturforschung A ◽

10.1515/zna-2019-0227 ◽

2020 ◽

Vol 75 (2) ◽

pp. 175-182

Author(s):

Magdy E. Amin ◽

Mohamed Moubark ◽

Yasmin Amin

Keyword(s):

Magnetic Field ◽

Ising Model ◽

Boundary Conditions ◽

Finite Size ◽

Scaling Functions ◽

Finite Size Scaling ◽

One Dimensional ◽

Various Boundary Conditions ◽

The One ◽

Bulk Case

AbstractThe one-dimensional Ising model with various boundary conditions is considered. Exact expressions for the thermodynamic and magnetic properties of the model using different kinds of boundary conditions [Dirichlet (D), Neumann (N), and a combination of Neumann–Dirichlet (ND)] are presented in the absence (presence) of a magnetic field. The finite-size scaling functions for internal energy, heat capacity, entropy, magnetisation, and magnetic susceptibility are derived and analysed as function of the temperature and the field. We show that the properties of the one-dimensional Ising model is affected by the finite size of the system and the imposed boundary conditions. The thermodynamic limit in which the finite-size functions approach the bulk case is also discussed.

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Screening of the magnetic field by magnetic monopoles in spin ice

JETP Letters ◽

10.1134/s0021364011070095 ◽

2011 ◽

Vol 93 (7) ◽

pp. 384-387 ◽

Cited By ~ 12

Author(s):

I. A. Ryzhkin ◽

M. I. Ryzhkin

Keyword(s):

Magnetic Field ◽

Magnetic Monopoles ◽

Spin Ice ◽

The Magnetic Field

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Tension-free Dirac strings and steered magnetic charges in 3D artificial spin ice

10.21203/rs.3.rs-266861/v1 ◽

2021 ◽

Author(s):

Sabri Koraltan ◽

Florian Slanovc ◽

Florian Bruckner ◽

Cristiano Nisoli ◽

Andrii Chumak ◽

...

Keyword(s):

Data Storage ◽

Magnetic Monopoles ◽

Data Transport ◽

Spin Ice ◽

New Paradigm ◽

Micromagnetic Simulations ◽

Tension Free ◽

Artificial Spin Ice ◽

Binary Information ◽

And Storage

Abstract 3D nano-architectures present a new paradigm in modern condensed matter physics with numerous applications in photonics, biomedicine, and spintronics. They are promising for the realisation of 3D magnetic nano-networks for ultra-fast and low-energy data storage. Frustration in these systems can lead to magnetic charges or magnetic monopoles, which can function as mobile, binary information carriers. However, Dirac strings in 2D artificial spin ices bind magnetic charges, while 3D dipolar counterparts require cryogenic temperatures for their stability. Here, we present a micromagnetic study of a highly-frustrated 3D artificial spin ice harboring tension-free Dirac strings with unbound magnetic charges at room temperature. We use micromagnetic simulations to demonstrate that the mobility threshold for magnetic charges is by 2 eV lower than their unbinding energy. By applying global magnetic fields, we steer magnetic charges in a given direction omitting unintended switchings. The introduced system paves a way towards 3D magnetic networks for data transport and storage.

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Chiral nature of magnetic monopoles in artificial spin ice

New Journal of Physics ◽

10.1088/1367-2630/15/3/035026 ◽

2013 ◽

Vol 15 (3) ◽

pp. 035026 ◽

Cited By ~ 28

Author(s):

N Rougemaille ◽

F Montaigne ◽

B Canals ◽

M Hehn ◽

H Riahi ◽

...

Keyword(s):

Magnetic Monopoles ◽

Spin Ice ◽

Artificial Spin Ice

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Emergent magnetic monopole dynamics in macroscopically degenerate artificial spin ice

Science Advances ◽

10.1126/sciadv.aav6380 ◽

2019 ◽

Vol 5 (2) ◽

pp. eaav6380 ◽

Cited By ~ 40

Author(s):

Alan Farhan ◽

Michael Saccone ◽

Charlotte F. Petersen ◽

Scott Dhuey ◽

Rajesh V. Chopdekar ◽

...

Keyword(s):

Magnetic Monopole ◽

Topological Defects ◽

Magnetic Monopoles ◽

Real Space ◽

Spin Ice ◽

Solid State Physics ◽

Pinch Point ◽

Topological Excitations ◽

Artificial Spin Ice ◽

Hückel Theory

Magnetic monopoles, proposed as elementary particles that act as isolated magnetic south and north poles, have long attracted research interest as magnetic analogs to electric charge. In solid-state physics, a classical analog to these elusive particles has emerged as topological excitations within pyrochlore spin ice systems. We present the first real-time imaging of emergent magnetic monopole motion in a macroscopically degenerate artificial spin ice system consisting of thermally activated Ising-type nanomagnets lithographically arranged onto a pre-etched silicon substrate. A real-space characterization of emergent magnetic monopoles within the framework of Debye-Hückel theory is performed, providing visual evidence that these topological defects act like a plasma of Coulomb-type magnetic charges. In contrast to vertex defects in a purely two-dimensional artificial square ice, magnetic monopoles are free to evolve within a divergence-free vacuum, a magnetic Coulomb phase, for which features in the form of pinch-point singularities in magnetic structure factors are observed.

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The effect of the size of the system, aspect ratio and impurities concentration on the dynamic of emergent magnetic monopoles in artificial spin ice systems

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2013.03.034 ◽

2013 ◽

Vol 340 ◽

pp. 120-126 ◽

Cited By ~ 5

Author(s):

Alejandro León

Keyword(s):

Aspect Ratio ◽

Magnetic Monopoles ◽

Spin Ice ◽

Artificial Spin Ice

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Tension-free Dirac strings and steered magnetic charges in 3D artificial spin ice

npj Computational Materials ◽

10.1038/s41524-021-00593-7 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Sabri Koraltan ◽

Florian Slanovc ◽

Florian Bruckner ◽

Cristiano Nisoli ◽

Andrii V. Chumak ◽

...

Keyword(s):

Data Storage ◽

Magnetic Monopoles ◽

Data Transport ◽

Spin Ice ◽

New Paradigm ◽

Micromagnetic Simulations ◽

Tension Free ◽

Artificial Spin Ice ◽

Binary Information ◽

And Storage

Abstract3D nano-architectures presents a new paradigm in modern condensed matter physics with numerous applications in photonics, biomedicine, and spintronics. They are promising for the realization of 3D magnetic nano-networks for ultra-fast and low-energy data storage. Frustration in these systems can lead to magnetic charges or magnetic monopoles, which can function as mobile, binary information carriers. However, Dirac strings in 2D artificial spin ices bind magnetic charges, while 3D dipolar counterparts require cryogenic temperatures for their stability. Here, we present a micromagnetic study of a highly frustrated 3D artificial spin ice harboring tension-free Dirac strings with unbound magnetic charges at room temperature. We use micromagnetic simulations to demonstrate that the mobility threshold for magnetic charges is by 2 eV lower than their unbinding energy. By applying global magnetic fields, we steer magnetic charges in a given direction omitting unintended switchings. The introduced system paves the way toward 3D magnetic networks for data transport and storage.

Download Full-text