Chiral bobbers and skyrmions in epitaxial FeGe/Si(111) films

Adam S. Ahmed, James Rowland, Bryan D. Esser, Sarah R. Dunsiger, David W. McComb, Mohit Randeria, Roland K. Kawakami

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We report experimental and theoretical evidence for the formation of chiral bobbers - an interfacial topological spin texture - in FeGe films grown by molecular beam epitaxy. After establishing the presence of skyrmions in FeGe/Si(111) thin-film samples through Lorentz transmission electron microscopy and the topological Hall effect, we perform magnetization measurements that reveal an inverse relationship between the film thickness and the slope of the susceptibility (dχ/dH). We present evidence for the evolution as a function of film thickness L from a skyrmion phase for L<LD/2 to a cone phase with chiral bobbers at the interface for L>LD/2, where LD∼70nm is the FeGe pitch length. We show using micromagnetic simulations that chiral bobbers, earlier predicted to be metastable, are in fact the stable ground state in the presence of an additional interfacial Rashba Dzyaloshinskii-Moriya interaction.

Original languageEnglish
Article number041401
Number of pages6
JournalPhysical Review B
Volume2
Issue number4
DOIs
Publication statusPublished - 17 Apr 2018
Externally publishedYes

Cite this

Ahmed, A. S., Rowland, J., Esser, B. D., Dunsiger, S. R., McComb, D. W., Randeria, M., & Kawakami, R. K. (2018). Chiral bobbers and skyrmions in epitaxial FeGe/Si(111) films. Physical Review B, 2(4), [041401]. https://doi.org/10.1103/PhysRevMaterials.2.041401
Ahmed, Adam S. ; Rowland, James ; Esser, Bryan D. ; Dunsiger, Sarah R. ; McComb, David W. ; Randeria, Mohit ; Kawakami, Roland K. / Chiral bobbers and skyrmions in epitaxial FeGe/Si(111) films. In: Physical Review B. 2018 ; Vol. 2, No. 4.
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abstract = "We report experimental and theoretical evidence for the formation of chiral bobbers - an interfacial topological spin texture - in FeGe films grown by molecular beam epitaxy. After establishing the presence of skyrmions in FeGe/Si(111) thin-film samples through Lorentz transmission electron microscopy and the topological Hall effect, we perform magnetization measurements that reveal an inverse relationship between the film thickness and the slope of the susceptibility (dχ/dH). We present evidence for the evolution as a function of film thickness L from a skyrmion phase for L<LD/2 to a cone phase with chiral bobbers at the interface for L>LD/2, where LD∼70nm is the FeGe pitch length. We show using micromagnetic simulations that chiral bobbers, earlier predicted to be metastable, are in fact the stable ground state in the presence of an additional interfacial Rashba Dzyaloshinskii-Moriya interaction.",
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Ahmed, AS, Rowland, J, Esser, BD, Dunsiger, SR, McComb, DW, Randeria, M & Kawakami, RK 2018, 'Chiral bobbers and skyrmions in epitaxial FeGe/Si(111) films' Physical Review B, vol. 2, no. 4, 041401. https://doi.org/10.1103/PhysRevMaterials.2.041401

Chiral bobbers and skyrmions in epitaxial FeGe/Si(111) films. / Ahmed, Adam S.; Rowland, James; Esser, Bryan D.; Dunsiger, Sarah R.; McComb, David W.; Randeria, Mohit; Kawakami, Roland K.

In: Physical Review B, Vol. 2, No. 4, 041401, 17.04.2018.

Research output: Contribution to journalArticleResearchpeer-review

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AU - Randeria, Mohit

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Ahmed AS, Rowland J, Esser BD, Dunsiger SR, McComb DW, Randeria M et al. Chiral bobbers and skyrmions in epitaxial FeGe/Si(111) films. Physical Review B. 2018 Apr 17;2(4). 041401. https://doi.org/10.1103/PhysRevMaterials.2.041401