Magnus induced diode effect for skyrmions in channels with periodic potentials

Author(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. 35, n. 1, p. 10-pg., 2023-01-11.

Abstract

Using a particle based model, we investigate the skyrmion dynamical behavior in a channel where the upper wall contains divots of one depth and the lower wall contains divots of a different depth. Under an applied driving force, skyrmions in the channels move with a finite skyrmion Hall angle that deflects them toward the upper wall for -x direction driving and the lower wall for +x direction driving. When the upper divots have zero height, the skyrmions are deflected against the flat upper wall for -x direction driving and the skyrmion velocity depends linearly on the drive. For +x direction driving, the skyrmions are pushed against the lower divots and become trapped, giving reduced velocities and a nonlinear velocity-force response. When there are shallow divots on the upper wall and deep divots on the lower wall, skyrmions get trapped for both driving directions; however, due to the divot depth difference, skyrmions move more easily under -x direction driving, and become strongly trapped for +x direction driving. The preferred -x direction motion produces what we call a Magnus diode effect since it vanishes in the limit of zero Magnus force, unlike the diode effects observed for asymmetric sawtooth potentials. We show that the transport curves can exhibit a series of jumps or dips, negative differential conductivity, and reentrant pinning due to collective trapping events. We also discuss how our results relate to recent continuum modeling on a similar skyrmion diode system. (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: 21/04941-0 - Dynamic behavior of Skyrmions in infinite Chiral Films in the presence of periodic Pinning potentials at zero temperature
• Grantee: José Carlos Bellizotti Souza
• Support Opportunities: Scholarships in Brazil - Scientific Initiation