Magnetic skyrmions are topological solitons with a nanoscale winding spin texture that hold promise for spintronics applications1-4. Skyrmions have so far been observed in a variety of magnets that exhibit nearly parallel alignment for neighbouring spins, but theoretically skyrmions with anti-parallel neighbouring spins are also possible. Such antiferromagnetic skyrmions may allow more flexible control than conventional ferromagnetic skyrmions5-10. Here, by combining neutron scattering measurements and Monte Carlo simulations, we show that a fractional antiferromagnetic skyrmion lattice is stabilized in MnSc2S4 through anisotropic couplings. The observed lattice is composed of three antiferromagnetically coupled sublattices, and each sublattice is a triangular skyrmion lattice that is fractionalized into two parts with an incipient meron (half-skyrmion) character11,12. Our work demonstrates that the theoretically proposed antiferromagnetic skyrmions can be stabilized in real materials and represents an important step towards their implementation in spintronic devices.

Abdus Salam International Centre for Theoretical Physics Associate Scheme Trieste Italy

Departamento de Ciencias Básicas Facultad de Ingeniería Universidad Nacional de La Plata La Plata Argentina

Departamento de Física Facultad de Ciencias Exactas Universidad Nacional de La Plata La Plata Argentina

Department of Condensed Matter Physics Faculty of Mathematics and Physics Charles University Prague Czech Republic

Department of Quantum Matter Physics University of Geneva Geneva Switzerland

Experimental Physics 5 University of Augsburg Augsburg Germany

Institut Laue Langevin Grenoble France

Institute for Quantum Electronics ETH Zürich Zurich Switzerland

Institute of Applied Physics Chisinau Republic of Moldova

Institute of Physics École Polytechnique Fédérale de Lausanne Lausanne Switzerland

Instituto de Física de Líquidos y Sistemas Biológicos UNLP CONICET Facultad de Ciencias Exactas La Plata Argentina

Jülich Center for Neutron Science Heinz Maier Leibnitz Zentrum Forshungszentrum Jülich GmbH Garching Germany

Laboratory for Neutron Scattering and Imaging Paul Scherrer Institut Villigen Switzerland

Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge TN USA

Neutron Science Division Oak Ridge National Laboratory Oak Ridge TN USA

Neutrons and Muons Research Division Paul Scherrer Institut Villigen Switzerland

RIKEN Center for Emergent Matter Science Wako Japan

Université Grenoble Alpes CEA INAC MEM Grenoble France

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Antiferromagnetic half-skyrmions electrically generated and controlled at room temperature