Clogging, diode and collective effects of skyrmions in funnel geometries
Using a particle-based model, we examine the collective dynamics of skyrmions interacting with a funnel potential under dc driving as the skyrmion density and relative strength of the Magnus and damping terms are varied. For driving in the easy direction, we find that increasing the skyrmion density...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022-01-01
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| Series: | New Journal of Physics |
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| Online Access: | https://doi.org/10.1088/1367-2630/ac9749 |
| _version_ | 1797748810275880960 |
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| author | J C Bellizotti Souza N P Vizarim C J O Reichhardt C Reichhardt P A Venegas |
| author_facet | J C Bellizotti Souza N P Vizarim C J O Reichhardt C Reichhardt P A Venegas |
| author_sort | J C Bellizotti Souza |
| collection | DOAJ |
| description | Using a particle-based model, we examine the collective dynamics of skyrmions interacting with a funnel potential under dc driving as the skyrmion density and relative strength of the Magnus and damping terms are varied. For driving in the easy direction, we find that increasing the skyrmion density reduces the average skyrmion velocity due to jamming of skyrmions near the funnel opening, while the Magnus force causes skyrmions to accumulate on one side of the funnel array. For driving in the hard direction, there is a critical skyrmion density below which the skyrmions become trapped. Above this critical value, a clogging effect appears with multiple depinning and repinning states where the skyrmions can rearrange into different clogged configurations, while at higher drives, the velocity-force curves become continuous. When skyrmions pile up near the funnel opening, the effective size of the opening is reduced and the passage of other skyrmions is blocked by the repulsive skyrmion–skyrmion interactions. We observe a strong diode effect in which the critical depinning force is higher and the velocity response is smaller for hard direction driving. As the ratio of Magnus force to dissipative term is varied, the skyrmion velocity varies in a non-linear and non-monotonic way due to the pile up of skyrmions on one side of the funnels. At high Magnus forces, the clogging effect for hard direction driving is diminished. |
| first_indexed | 2024-03-12T16:10:11Z |
| format | Article |
| id | doaj.art-206a34f35c674280ae9d09584e3a8930 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:10:11Z |
| publishDate | 2022-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-206a34f35c674280ae9d09584e3a89302023-08-09T14:09:08ZengIOP PublishingNew Journal of Physics1367-26302022-01-01241010303010.1088/1367-2630/ac9749Clogging, diode and collective effects of skyrmions in funnel geometriesJ C Bellizotti Souza0N P Vizarim1https://orcid.org/0000-0002-2735-615XC J O Reichhardt2https://orcid.org/0000-0002-3487-5089C Reichhardt3P A Venegas4Departamento de Física, Faculdade de Ciências, Unesp-Universidade Estadual Paulista , CP 473, 17033-360 Bauru, SP, BrazilPOSMAT—Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, Faculdade de Ciências, Universidade Estadual Paulista—UNESP , Bauru, SP, CP 473, 17033-360, Brazil; Department of Physics, University of Antwerp , Groenenborgerlaan 171, B-2020 Antwerp, BelgiumTheoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States of AmericaTheoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States of AmericaDepartamento de Física, Faculdade de Ciências, Unesp-Universidade Estadual Paulista , CP 473, 17033-360 Bauru, SP, BrazilUsing a particle-based model, we examine the collective dynamics of skyrmions interacting with a funnel potential under dc driving as the skyrmion density and relative strength of the Magnus and damping terms are varied. For driving in the easy direction, we find that increasing the skyrmion density reduces the average skyrmion velocity due to jamming of skyrmions near the funnel opening, while the Magnus force causes skyrmions to accumulate on one side of the funnel array. For driving in the hard direction, there is a critical skyrmion density below which the skyrmions become trapped. Above this critical value, a clogging effect appears with multiple depinning and repinning states where the skyrmions can rearrange into different clogged configurations, while at higher drives, the velocity-force curves become continuous. When skyrmions pile up near the funnel opening, the effective size of the opening is reduced and the passage of other skyrmions is blocked by the repulsive skyrmion–skyrmion interactions. We observe a strong diode effect in which the critical depinning force is higher and the velocity response is smaller for hard direction driving. As the ratio of Magnus force to dissipative term is varied, the skyrmion velocity varies in a non-linear and non-monotonic way due to the pile up of skyrmions on one side of the funnels. At high Magnus forces, the clogging effect for hard direction driving is diminished.https://doi.org/10.1088/1367-2630/ac9749skyrmioncloggingjammingcollective effectsskyrmion dynamics |
| spellingShingle | J C Bellizotti Souza N P Vizarim C J O Reichhardt C Reichhardt P A Venegas Clogging, diode and collective effects of skyrmions in funnel geometries New Journal of Physics skyrmion clogging jamming collective effects skyrmion dynamics |
| title | Clogging, diode and collective effects of skyrmions in funnel geometries |
| title_full | Clogging, diode and collective effects of skyrmions in funnel geometries |
| title_fullStr | Clogging, diode and collective effects of skyrmions in funnel geometries |
| title_full_unstemmed | Clogging, diode and collective effects of skyrmions in funnel geometries |
| title_short | Clogging, diode and collective effects of skyrmions in funnel geometries |
| title_sort | clogging diode and collective effects of skyrmions in funnel geometries |
| topic | skyrmion clogging jamming collective effects skyrmion dynamics |
| url | https://doi.org/10.1088/1367-2630/ac9749 |
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