Skyrmion transport and annihilation in funnel geometries

Author(s)

Rocha, F. S. ; Souza, J. C. Bellizotti ; Vizarim, N. P. ; Reichhardt, C. J. O. ; Reichhardt, C. ; Venegas, P. A.

• Document type: Journal article
• Source: JOURNAL OF PHYSICS-CONDENSED MATTER; v. 36, n. 11, p. 12-pg., 2024-03-20.

Abstract

Using atomistic simulations, we have investigated the transport and annihilation of skyrmions interacting with a funnel array under a current applied perpendicular to the funnel axis. We find that transport without annihilation is possible at low currents, when the motion is dominated by skyrmion-skyrmion interactions and skyrmions push each other through the funnel opening. Skyrmion annihilation occurs for higher currents when skyrmions in the upper half of the sample exert pressure on skyrmions in the bottom half of the sample due to the external current. Upon interacting with the funnel wall, the skyrmions undergo a size reduction that makes it easier for them to pass through the funnel opening. We find five phases as a function of the applied current and the size of the funnel opening: (i) pinned, (ii) transport without annihilation, (iii) transport with annihilation, (iv) complete annihilation, and (v) a reentrant pinning phase that only occurs for very narrow openings. Our findings provide insight into how to control skyrmion transport using funnel arrays by delineating regimes in which transport of skyrmions is possible as well as the conditions under which annihilation occurs. (AU)

• FAPESP's process: 17/20976-3 - Dynamic behavior of skyrmions under the influence of periodic pinning in chiral magnetic infinite thin films
• Grantee: Nicolas Porto Vizarim
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 22/14053-8 - Study of Skyrmions Behavior in Magnetic Materials with Defects
• Grantee: José Carlos Bellizotti Souza
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 21/04655-8 - Machine learning and its applications in quantum physics: metrology, thermology, phase transitions and dynamical decoupling
• Grantee: Felipe Fernandes Fanchini
• Support Opportunities: Regular Research Grants