Fractional antiferromagnetic skyrmion lattice induced by anisotropic couplings

GAO, SHANG; ROSALES, H. DIEGO; GÓMEZ ALBARRACÍN, FLAVIA A.; TSURKAN, VLADIMIR; KAUR, GURATINDER; FENNELL, TOM; STEFFENS, PAUL; BOEHM, MARTIN; CERMÁK, PETR; SCHNEIDEWIND, ASTRID; RESSOUCHE, ERIC; CABRA, DANIEL C.; RÜEGG, CHRISTIAN; ZAHARKO, OKSANA

NATURE

NATURE PUBLISHING GROUP

Año: 2020 vol. 586 p. 37 - 41

0028-0836

Magnetic skyrmions are topological solitons with a nanoscale winding spin texture that hold promise for spintronics applications1,2,3,4. 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 skyrmions [5,6,7,8,9,10]. 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) character [11,12]. 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.