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.

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
• Public URL: https://durham-repository.worktribe.com/output/1185505