Enhanced skyrmion metastability under applied strain in FeGe

Littlehales, M.T.; Turnbull, L.A.; Wilson, M.N.; Birch, M.T.; Popescu, H.; Jaouen, N.; Verezhak, J.A.T.; Balakrishnan, G.; Hatton, P.D.

doi:10.1103/physrevb.106.214434

Enhanced skyrmion metastability under applied strain in FeGe

Littlehales, M.T.; Turnbull, L.A.; Wilson, M.N.; Birch, M.T.; Popescu, H.; Jaouen, N.; Verezhak, J.A.T.; Balakrishnan, G.; Hatton, P.D.

Authors

Matt Littlehales matthew.t.littlehales@durham.ac.uk
PGR Student Doctor of Philosophy

Luke Turnbull l.a.turnbull@durham.ac.uk
PGR Student Doctor of Philosophy

M.N. Wilson

M.T. Birch

H. Popescu

N. Jaouen

J.A.T. Verezhak

G. Balakrishnan

Professor Peter Hatton p.d.hatton@durham.ac.uk
Professor

Abstract

Mechanical straining of skyrmion hosting materials has previously demonstrated increased phase stability through the expansion of the skyrmion equilibrium pocket. Additionally, metastable skyrmions can be generated via rapid field cooling to form significant skyrmion populations at low temperatures. Using small-angle x-ray scattering and x-ray holographic imaging on a thermally strained 200-nm-thick FeGe lamella, we observe temperature-induced strain effects on the structure and metastability of the skyrmion lattice. We find that in this sample orientation ( H ∥ [ ¯ 1 1 0 ] ) with no strain, metastable skyrmions produced by field cooling through the equilibrium skyrmion pocket vanish from the sample upon dropping below the well-known helical reorientation temperature. However, when strain is applied along the [ 1 1 0 ] axis, and this procedure is repeated, a substantial volume fraction of metastable skyrmions persist upon cooling below this temperature down to 100 K. Additionally, we observe a large number of skyrmions retained after a complete magnetic field polarity reversal, implying that the metastable energy barrier protecting skyrmions from decay is enhanced.

Citation

Littlehales, M., Turnbull, L., Wilson, M., Birch, M., Popescu, H., Jaouen, N., …Hatton, P. (2022). Enhanced skyrmion metastability under applied strain in FeGe. Physical Review B, 106(21), Article 214434. https://doi.org/10.1103/physrevb.106.214434

Journal Article Type	Article
Acceptance Date	Nov 29, 2022
Online Publication Date	Dec 26, 2022
Publication Date	Dec 1, 2022
Deposit Date	Jan 11, 2023
Publicly Available Date	Jan 11, 2023
Journal	Physical review B: Condensed matter and materials physics
Print ISSN	2469-9950
Electronic ISSN	2469-9969
Publisher	American Physical Society
Peer Reviewed	Peer Reviewed
Volume	106
Issue	21
Article Number	214434
DOI	https://doi.org/10.1103/physrevb.106.214434

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Copyright Statement
Reprinted with permission from the American Physical Society: Littlehales, M. T., Turnbull, L. A., Wilson, M. N., Birch, M. T., Popescu, H., Jaouen, N., Verezhak, J. A. T., Balakrishnan, G. & Hatton, P. D. (2022). Enhanced skyrmion metastability under applied strain in FeGe. Physical Review B 106(21): 214434. © (2022) by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.