The influence of antiferromagnetic spin cantings on the magnetic helix pitch in cubic helimagnets

Fuente: arXiv
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Main Authors: Chizhikov, Viacheslav A., Dmitrienko, Vladimir E.
Format: Preprint
Published: 2023
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author Chizhikov, Viacheslav A.
Dmitrienko, Vladimir E.
author_facet Chizhikov, Viacheslav A.
Dmitrienko, Vladimir E.
contents In cubic helimagnets MnSi and Cu2OSeO3 with their nearly isotropic magnetic properties, the magnetic structure undergoes helical deformation, which is almost completely determined by the helicoid wavenumber k = D / J, where magnetization field stiffness J is associated with isotropic spin exchange, and D is a pseudoscalar value characterizing the antisymmetric Dzyaloshinskii-Moriya (DM) interaction. While the wavenumber can be measured directly in a diffraction experiment, the values of J and D can be calculated from the constants of pair spin interactions, which enter as parameters into the Heisenberg energy. However, the available analytical expression for D, which is of the first order in the spin-orbit coupling (SOC), has significant problems with accuracy. Here we show that hardly observable distortions of the magnetic structure, namely the antiferromagnetic spin cantings, can significantly change the constant D in the next approximation in SOC, thus affecting the wavenumber of magnetic helicoids. The obtained analytical expressions agree with the results of numerical simulation of magnetic helices in Cu2OSeO3 to within a few percent.
format Preprint
id arxiv_https___arxiv_org_abs_2309_14480
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle The influence of antiferromagnetic spin cantings on the magnetic helix pitch in cubic helimagnets
Chizhikov, Viacheslav A.
Dmitrienko, Vladimir E.
Strongly Correlated Electrons
In cubic helimagnets MnSi and Cu2OSeO3 with their nearly isotropic magnetic properties, the magnetic structure undergoes helical deformation, which is almost completely determined by the helicoid wavenumber k = D / J, where magnetization field stiffness J is associated with isotropic spin exchange, and D is a pseudoscalar value characterizing the antisymmetric Dzyaloshinskii-Moriya (DM) interaction. While the wavenumber can be measured directly in a diffraction experiment, the values of J and D can be calculated from the constants of pair spin interactions, which enter as parameters into the Heisenberg energy. However, the available analytical expression for D, which is of the first order in the spin-orbit coupling (SOC), has significant problems with accuracy. Here we show that hardly observable distortions of the magnetic structure, namely the antiferromagnetic spin cantings, can significantly change the constant D in the next approximation in SOC, thus affecting the wavenumber of magnetic helicoids. The obtained analytical expressions agree with the results of numerical simulation of magnetic helices in Cu2OSeO3 to within a few percent.
title The influence of antiferromagnetic spin cantings on the magnetic helix pitch in cubic helimagnets
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2309.14480