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Title: Static Hopf Solitons and Knotted Emergent Fields in Solid-State Noncentrosymmetric Magnetic Nanostructures

Journal Article · · Physical Review Letters
 [1];  [1]
  1. Univ. of Colorado, Boulder, CO (United States)

Two-dimensional topological solitons, commonly called Skyrmions, are extensively studied in solid-state magnetic nanostructures and promise many spintronics applications. However, three-dimensional topological solitons dubbed hopfions have not been demonstrated as stable spatially localized structures in solid-state magnetic materials. Here we model the existence of such static solitons with different Hopf index values in noncentrosymmetric solid magnetic nanostructures with a perpendicular interfacial magnetic anisotropy. We show how this surface anisotropy, along with the Dzyaloshinskii-Moriya interactions and the geometry of nanostructures, stabilize hopfions. We show knots in emergent field lines and computer simulate Lorentz transmission electron microscopy images of such solitonic configurations to guide their experimental discovery in magnetic solids.

Research Organization:
Univ. of Colorado, Boulder, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE
Grant/Contract Number:
SC0019293; ER46921; SC0010305
OSTI ID:
1594985
Alternate ID(s):
OSTI ID: 1479857
Journal Information:
Physical Review Letters, Vol. 121, Issue 18; ISSN 0031-9007
Publisher:
American Physical Society (APS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 63 works
Citation information provided by
Web of Science

References (55)

Landau–de Gennes modelling of nematic liquid crystal colloids journal August 2009
Knots in the Skyrme–Faddeev model journal August 2007
Skyrmions on the track journal March 2013
An Expression of Hopf's Invariant as an Integral journal May 1947
Static three-dimensional topological solitons in fluid chiral ferromagnets and colloids journal December 2016
Partially Dual Variables in SU(2) Yang-Mills Theory journal February 1999
Manipulation of the spin helix in FeGe thin films and FeGe/Fe multilayers journal October 2015
Perpendicular magnetic anisotropy at transition metal/oxide interfaces and applications journal June 2017
Thermodynamically stable magnetic vortex states in magnetic crystals journal December 1994
Extended Skyrmion Phase in Epitaxial FeGe ( 111 ) Thin Films journal June 2012
Hidden symmetry and knot solitons in a charged two-condensate Bose system journal February 2002
Linear momentum in ferromagnets journal March 1987
Dynamical toroidal Hopfions in a ferromagnet with easy-axis anisotropy journal December 2009
Knots as Stable Soliton Solutions in a Three-Dimensional Classical Field Theory journal November 1998
Near room-temperature formation of a skyrmion crystal in thin-films of the helimagnet FeGe journal December 2010
Dynamics of Skyrmion Crystals in Metallic Thin Films journal September 2011
Topological Solitons book January 2010
Topological properties and dynamics of magnetic skyrmions journal December 2013
Spin-wave spectroscopy of the Dzyaloshinskii-Moriya interaction in room-temperature chiral magnets hosting skyrmions journal June 2017
Scattering of knotted vortices (Hopfions) in the Faddeev–Skyrme model journal January 2012
Real-space observation of a two-dimensional skyrmion crystal journal June 2010
Observation of the magnetic flux and three-dimensional structure of skyrmion lattices by electron holography journal April 2014
Topological transformations of Hopf solitons in chiral ferromagnets and liquid crystals journal January 2018
Quantitative Fresnel Lorentz microscopy and the transport of intensity equation journal March 2006
A new class of chiral materials hosting magnetic skyrmions beyond room temperature journal July 2015
Skyrmion Knots in Frustrated Magnets journal June 2017
Experimental observation of chiral magnetic bobbers in B20-type FeGe journal April 2018
Skyrmion Lattice in a Chiral Magnet journal February 2009
Unwinding of a Skyrmion Lattice by Magnetic Monopoles journal May 2013
Comments on Nonlinear Wave Equations as Models for Elementary Particles journal September 1964
Stable knot-like structures in classical field theory journal May 1997
A strategy for the design of skyrmion racetrack memories journal October 2014
Control of morphology and formation of highly geometrically confined magnetic skyrmions journal June 2017
Vortex rings in ferromagnets: Numerical simulations of the time-dependent three-dimensional Landau-Lifshitz equation journal November 2007
Three-dimensional structure and multistable optical switching of triple-twisted particle-like excitations in anisotropic fluids journal December 2009
Temperature and Magnetic Field Dependence of the Internal and Lattice Structures of Skyrmions by Off-Axis Electron Holography journal February 2017
Diversity of Knot Solitons in Liquid Crystals Manifested by Linking of Preimages in Torons and Hopfions journal January 2017
Chiral modulations and reorientation effects in MnSi thin films journal March 2012
Propagating Magnetic Vortex Rings in Ferromagnets journal February 1999
Generalization of the Landau-Lifshitz-Gilbert Equation for Conducting Ferromagnets journal February 2009
Magnetic anisotropy in metallic multilayers journal November 1996
Stable Skyrmions in Two-Component Bose-Einstein Condensates journal February 2002
Skyrmionic magnetization configurations at chiral magnet/ferromagnet heterostructures journal February 2016
Selecta Heinz hopf journal January 1965
Topological solitons journal December 2012
Selecta Heinz Hopf. journal April 1966
Knots in the Skyrme-Faddeev model text January 2007
Skyrmion Lattice in a Chiral Magnet text January 2009
Dynamical Toroidal Hopfions in a Ferromagnet with Easy-Axis Anisotropy text January 2009
Dynamics of Skyrmion Crystals in Metallic Thin Films text January 2011
A new class of chiral materials hosting magnetic skyrmions beyond room temperature text January 2015
Diversity of knot solitons in liquid crystals manifested by linking of preimages in torons and hopfions text January 2017
Skyrmion knots in frustrated magnets text January 2017
Hidden symmetry and knot solitons in a charged two-condensate Bose system text January 2001
Partially Dual variables in SU(2) Yang-Mills Theory text January 1998

Cited By (6)

Spin, Orbital, Weyl and Other Glasses in Topological Superfluids journal December 2018
X-ray ptychography on low-dimensional hard-condensed matter materials journal March 2019
Launching a new dimension with 3D magnetic nanostructures journal January 2020
Skyrmion-electronics: writing, deleting, reading and processing magnetic skyrmions toward spintronic applications journal January 2020
Three-dimensional crystals of adaptive knots journal September 2019
Three-dimensional crystals of adaptive knots text January 2019

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