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Title: Magnus-induced dynamics of driven skyrmions on a quasi-one-dimensional periodic substrate

Here we numerically examine driven skyrmions interacting with a periodic quasi-one-dimensional substrate where the driving force is applied either parallel or perpendicular to the substrate periodicity direction. For perpendicular driving, the particles in a purely overdamped system simply slide along the substrate minima; however, for skyrmions where the Magnus force is relevant, we find that a rich variety of dynamics can arise. In the single skyrmion limit, the skyrmion motion is locked along the driving or longitudinal direction for low drives, while at higher drives a transition occurs to a state in which the skyrmion moves both transverse and longitudinal to the driving direction. Within the longitudinally locked phase we find a pronounced speedup effect that occurs when the Magnus force aligns with the external driving force, while at the transition to transverse and longitudinal motion, the skyrmion velocity drops, producing negative differential conductivity. For collectively interacting skyrmion assemblies, the speedup effect is still present and we observe a number of distinct dynamical phases, including a sliding smectic phase, a disordered or moving liquid phase, a moving hexatic phase, and a moving crystal phase. The transitions between the dynamic phases produce distinct features in the structure of the skyrmion latticemore » and in the velocity-force curves. Lastly, we map these different phases as a function of the ratio of the Magnus term to the dissipative term, the substrate strength, the commensurability ratio, and the magnitude of the driving force.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
LA-UR-16-23792
Journal ID: ISSN 2469-9950; TRN: US1800648
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 94; Journal Issue: 9; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 36 MATERIALS SCIENCE; Material Science
OSTI Identifier:
1414122
Alternate Identifier(s):
OSTI ID: 1324376

Reichhardt, Charles, and Reichhardt, Cynthia Jane. Magnus-induced dynamics of driven skyrmions on a quasi-one-dimensional periodic substrate. United States: N. p., Web. doi:10.1103/PhysRevB.94.094413.
Reichhardt, Charles, & Reichhardt, Cynthia Jane. Magnus-induced dynamics of driven skyrmions on a quasi-one-dimensional periodic substrate. United States. doi:10.1103/PhysRevB.94.094413.
Reichhardt, Charles, and Reichhardt, Cynthia Jane. 2016. "Magnus-induced dynamics of driven skyrmions on a quasi-one-dimensional periodic substrate". United States. doi:10.1103/PhysRevB.94.094413. https://www.osti.gov/servlets/purl/1414122.
@article{osti_1414122,
title = {Magnus-induced dynamics of driven skyrmions on a quasi-one-dimensional periodic substrate},
author = {Reichhardt, Charles and Reichhardt, Cynthia Jane},
abstractNote = {Here we numerically examine driven skyrmions interacting with a periodic quasi-one-dimensional substrate where the driving force is applied either parallel or perpendicular to the substrate periodicity direction. For perpendicular driving, the particles in a purely overdamped system simply slide along the substrate minima; however, for skyrmions where the Magnus force is relevant, we find that a rich variety of dynamics can arise. In the single skyrmion limit, the skyrmion motion is locked along the driving or longitudinal direction for low drives, while at higher drives a transition occurs to a state in which the skyrmion moves both transverse and longitudinal to the driving direction. Within the longitudinally locked phase we find a pronounced speedup effect that occurs when the Magnus force aligns with the external driving force, while at the transition to transverse and longitudinal motion, the skyrmion velocity drops, producing negative differential conductivity. For collectively interacting skyrmion assemblies, the speedup effect is still present and we observe a number of distinct dynamical phases, including a sliding smectic phase, a disordered or moving liquid phase, a moving hexatic phase, and a moving crystal phase. The transitions between the dynamic phases produce distinct features in the structure of the skyrmion lattice and in the velocity-force curves. Lastly, we map these different phases as a function of the ratio of the Magnus term to the dissipative term, the substrate strength, the commensurability ratio, and the magnitude of the driving force.},
doi = {10.1103/PhysRevB.94.094413},
journal = {Physical Review B},
number = 9,
volume = 94,
place = {United States},
year = {2016},
month = {9}
}