Increased lifetime of metastable skyrmions by controlled doping

Birch, M.T.; Takagi, R.; Seki, S.; Wilson, M.N.; Kagawa, F.; Štefančič, A.; Balakrishnan, G.; Fan, R.; Steadman, P.; Ottley, C.J.; Crisanti, M.; Cubitt, R.; Lancaster, T.; Tokura, Y.; Hatton, P.D.

Abstract

Previous observations of metastable magnetic skyrmions have shown that close to the equilibrium pocket the metastable state has a short lifetime, and therefore, rapid cooling is required to generate a significant skyrmion population at low temperatures. Here, we report that the lifetime of metastable skyrmions in crystals of Cu2OSeO3 is extended by a factor of 50 with the introduction of only 2.5% zinc doping, allowing over 50% of the population to survive when field cooling at a rate of just 1 K/min. Our systematic study suggests that the lifetime enhancement is due to the increase in the pinning site density, rather than an alteration to the energy barrier of the decay process. We expect that doping can be exploited to control the lifetime of the metastable SkL state in other chiral magnets, offering a method of engineering skyrmion materials towards application in future devices.

Citation

Birch, M., Takagi, R., Seki, S., Wilson, M., Kagawa, F., Štefančič, A., Balakrishnan, G., Fan, R., Steadman, P., Ottley, C., Crisanti, M., Cubitt, R., Lancaster, T., Tokura, Y., & Hatton, P. (2019). Increased lifetime of metastable skyrmions by controlled doping. Physical review B - Condensed Matter and Materials Physics, 100(1), Article 014425. https://doi.org/10.1103/physrevb.100.014425

• Journal Article Type: Article
• Online Publication Date: Jul 22, 2019
• Publication Date: Jul 31, 2019
• Deposit Date: Jul 25, 2019
• Publicly Available Date: Jul 25, 2019
• Journal: Physical review B - Condensed Matter and Materials Physics
• Print ISSN: 1098-0121
• Electronic ISSN: 1550-235X
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 100
• Issue: 1
• Article Number: 014425
• DOI: https://doi.org/10.1103/physrevb.100.014425
• Public URL: https://durham-repository.worktribe.com/output/1326461