Observation of magnetic vortex pairs at room temperature in a planar α-Fe2O3/Co heterostructure

Abstract

Vortices are among the simplest topological structures, and occur whenever a flow field `whirls' around a one-dimensional core. They are ubiquitous to many branches of physics, from fluid dynamics to superconductivity and superfluidity, and are even predicted by some unified theories of particle interactions, where they might explain some of the largest-scale structures seen in today's Universe. In the crystalline state, vortex formation is rare, since it is generally hampered by long-range interactions: in ferroic materials (ferromagnetic and ferroelectric), vortices are only observed when the effects of the dipole-dipole interaction is modified by confinement at the nanoscale, or when the parameter associated with the vorticity does not couple directly with strain. Here, we present the discovery of a novel form of vortices in antiferromagnetic (AFM) hematite ($\alpha$-Fe${}_2$O${}_3$) epitaxial films, in which the primary whirling parameter is the staggered magnetisation. Remarkably, ferromagnetic (FM) topological objects with the same vorticity and winding number of the $\alpha$-Fe${}_2$O${}_3$ vortices are imprinted onto an ultra-thin Co ferromagnetic over-layer by interfacial exchange. Our data suggest that the ferromagnetic vortices may be merons (half-skyrmions, carrying an out-of-plane core magnetisation), and indicate that the vortex/meron pairs can be manipulated by the application of an in-plane magnetic field, H${}_{\parallel }$, giving rise to large-scale vortex-antivortex annihilation.

arXiv comment16 pages, 4 figures

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Cited by in corpus (35)

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• Electrical Switching of Tristate Antiferromagnetic Néel Order in $\alpha$-Fe${}_2$O${}_3$ Epitaxial Films
• Meron-Like Topological Spin Defects in Monolayer CrCl3
• Current-Induced Dynamics and Chaos of Antiferromagnetic Bimerons
• Static and dynamic properties of bimerons in a frustrated ferromagnetic monolayer
• Long-distance propagation of high-velocity antiferromagnetic spin waves
• Dynamics of ferromagnetic bimerons driven by spin currents and magnetic fields
• Homochiral antiferromagnetic merons, antimerons and bimerons realized in synthetic antiferromagnets
• Spontaneous generation and active manipulation of real-space optical vortex
• Antiferromagnetic insulatronics: spintronics in insulating 3d metal oxides with antiferromagnetic coupling
• Topological transport of deconfined hedgehogs in magnets
• Traveling skyrmions in chiral antiferromagnets
• Role of substrate clamping on anisotropy and domain structure in the canted antiferromagnet $\alpha$-Fe${}_2$O${}_3$
• Analogy between the magnetic dipole moment at the surface of a magnetoelectric and the electric charge at the surface of a ferroelectric
• Local Electronic Structure and Dynamics of Muon-Polaron Complexes in Fe${}_2$O${}_3$
• Emergence of stable meron quartets in twisted magnets
• Bimerons create bimerons: proliferation and aggregation induced by currents and magnetic fields
• Spatially reconfigurable topological textures in freestanding antiferromagnetic nanomembranes
• Skyrmionics in correlated oxides
• Large ordered moment with strong easy-plane anisotropy and vortex-domain pattern in the kagome ferromagnet Fe${}_3$Sn
• Domain periodicity in an easy-plane antiferromagnet with Dzyaloshinskii-Moriya interaction
• Micromagnetic modelling and imaging of vortex|merons structures in an oxide|metal heterostructure
• Magnetic Bimeron Traveling on the Domain Wall
• Topological invariants of vortices, merons, skyrmions, and their combinations in continuous and discrete systems
• Tuning of non-paraxial effects of the Laguerre-Gaussian beam interacting with the two-component Bose-Einstein condensates
• A route towards stable homochiral topological textures in A-type antiferromagnets
• Transfer of orbital angular momentum superposition from asymmetric Laguerre-Gaussian beam to Bose-Einstein Condensate
• Observation and formation mechanism of 360° domain wall rings in Synthetic Anti-Ferromagnets with interlayer chiral interactions
• Determination of optimal experimental conditions for accurate 3D reconstruction of the magnetization vector via XMCD-PEEM
• Renormalized analytic solution for the enstrophy cascade in two-dimensional quantum turbulence
• Multi-Meron Interactions and Statistics in Two-Dimensional Materials
• Role of isotropic and anisotropic Dzyaloshinskii-Moriya interaction on skyrmions, merons and antiskyrmions in the $C_{nv}$ symmetric system
• Emergence of Meron Kekulé lattices in twisted Néel antiferromagnets
• Vortex propagation and phase transitions in a chiral antiferromagnetic nanostripe