Lifetime of skyrmions in discrete systems with infinitesimal lattice constant

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Lifetime of skyrmions in discrete systems with infinitesimal lattice constant. / Potkina, M.N.; Lobanov, I.S.; Jónsson, H.; Uzdin, V.M.

In: Journal of Magnetism and Magnetic Materials, Vol. 549, 168974, 01.05.2022.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{7974bdc261a34f038848ac63d6c120d7,

title = "Lifetime of skyrmions in discrete systems with infinitesimal lattice constant",

abstract = "Topological protection of chiral magnetic structures is investigated by taking a two-dimensional magnetic skyrmion as an example. The skyrmion lifetime is calculated based on harmonic transition state theory for a discrete lattice model using various values of the ratio of the lattice constant and the skyrmion size. Parameters of the system corresponding to exchange, anisotropy and Dzyaloshinskii–Moriya interaction are chosen in such a way as to keep the energy and size of the skyrmion unchanged for small values of the lattice constant, using scaling relations derived from continuous micromagnetic description. The number of magnetic moments included in the calculations reaches more than a million. The results indicate that in the limit of infinitesimal lattice constant, the energy barrier for skyrmion collapse approaches the Belavin–Polyakov lower bound of the energy of a topological soliton in the -model, the entropy contribution to the pre-exponential factor in the Arrhenius rate expression for collapse approaches a constant and the skyrmion lifetime can, for large enough number of spins, correspond to thermally stable skyrmion at room temperature even without magnetic dipole–dipole interaction.",

keywords = "Chiral magnet, Lifetime, Skyrmion, Topological protection",

author = "M.N. Potkina and I.S. Lobanov and H. J{\'o}nsson and V.M. Uzdin",

note = "Publisher Copyright: {\textcopyright} 2022 Elsevier B.V.",

year = "2022",

month = may,

day = "1",

doi = "10.1016/j.jmmm.2021.168974",

language = "English",

volume = "549",

journal = "Journal of Magnetism and Magnetic Materials",

issn = "0304-8853",

publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Lifetime of skyrmions in discrete systems with infinitesimal lattice constant

AU - Potkina, M.N.

AU - Lobanov, I.S.

AU - Jónsson, H.

AU - Uzdin, V.M.

PY - 2022/5/1

Y1 - 2022/5/1

N2 - Topological protection of chiral magnetic structures is investigated by taking a two-dimensional magnetic skyrmion as an example. The skyrmion lifetime is calculated based on harmonic transition state theory for a discrete lattice model using various values of the ratio of the lattice constant and the skyrmion size. Parameters of the system corresponding to exchange, anisotropy and Dzyaloshinskii–Moriya interaction are chosen in such a way as to keep the energy and size of the skyrmion unchanged for small values of the lattice constant, using scaling relations derived from continuous micromagnetic description. The number of magnetic moments included in the calculations reaches more than a million. The results indicate that in the limit of infinitesimal lattice constant, the energy barrier for skyrmion collapse approaches the Belavin–Polyakov lower bound of the energy of a topological soliton in the -model, the entropy contribution to the pre-exponential factor in the Arrhenius rate expression for collapse approaches a constant and the skyrmion lifetime can, for large enough number of spins, correspond to thermally stable skyrmion at room temperature even without magnetic dipole–dipole interaction.

AB - Topological protection of chiral magnetic structures is investigated by taking a two-dimensional magnetic skyrmion as an example. The skyrmion lifetime is calculated based on harmonic transition state theory for a discrete lattice model using various values of the ratio of the lattice constant and the skyrmion size. Parameters of the system corresponding to exchange, anisotropy and Dzyaloshinskii–Moriya interaction are chosen in such a way as to keep the energy and size of the skyrmion unchanged for small values of the lattice constant, using scaling relations derived from continuous micromagnetic description. The number of magnetic moments included in the calculations reaches more than a million. The results indicate that in the limit of infinitesimal lattice constant, the energy barrier for skyrmion collapse approaches the Belavin–Polyakov lower bound of the energy of a topological soliton in the -model, the entropy contribution to the pre-exponential factor in the Arrhenius rate expression for collapse approaches a constant and the skyrmion lifetime can, for large enough number of spins, correspond to thermally stable skyrmion at room temperature even without magnetic dipole–dipole interaction.

KW - Chiral magnet

KW - Lifetime

KW - Skyrmion

KW - Topological protection

UR - https://www.sciencedirect.com/science/article/abs/pii/S0304885321011690

UR - http://www.scopus.com/inward/record.url?scp=85122654697&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/a6fa86bf-a6a3-381d-a47e-7d355e7f2463/

U2 - 10.1016/j.jmmm.2021.168974

DO - 10.1016/j.jmmm.2021.168974

M3 - Article

VL - 549

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

SN - 0304-8853

M1 - 168974

ER -

ID: 91285866