Néel-type skyrmion lattice with confined orientation in the polar magnetic semiconductor GaV4S8.
Following the early prediction of the skyrmion lattice (SkL)--a periodic array of spin vortices--it has been observed recently in various magnetic crystals mostly with chiral structure. Although non-chiral but polar crystals with Cnv symmetry were identified as ideal SkL hosts in pioneering theoretical studies, this archetype of SkL has remained experimentally unexplored. Here, we report the discovery of a SkL in the polar magnetic semiconductor GaV4S8 with rhombohedral (C3v) symmetry and easy axis anisotropy. The SkL exists over an unusually broad temperature range compared with other bulk crystals and the orientation of the vortices is not controlled by the external magnetic field, but instead confined to the magnetic easy axis. Supporting theory attributes these unique features to a new Néel-type of SkL describable as a superposition of spin cycloids in contrast to the Bloch-type SkL in chiral magnets described in terms of spin helices.
Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Magneto-optical Spectroscopy Research Group, 1111 Budapest, Hungary.|Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany.
I
I
Kézsmárki
Department of Physics, Budapest University of Technology and Economics and MTA-BME Lendület Magneto-optical Spectroscopy Research Group, 1111 Budapest, Hungary.
S
S
Bordács
Institut für Angewandte Photophysik, TU Dresden, D-01069 Dresden, Germany.
P
P
Milde
Institut für Angewandte Photophysik, TU Dresden, D-01069 Dresden, Germany.
E
E
Neuber
Institut für Angewandte Photophysik, TU Dresden, D-01069 Dresden, Germany.
L M
LM
Eng
Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
J S
JS
White
Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
H M
HM
Rønnow
Institut Laue-Langevin, 6 rue Jules Horowitz 38042 Grenoble, France.
C D
CD
Dewhurst
Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 229-8558, Japan.|PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan.
M
M
Mochizuki
Department of Physics and Mathematics, Aoyama Gakuin University, Sagamihara, Kanagawa 229-8558, Japan.
K
K
Yanai
Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501, Japan.
H
H
Nakamura
Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany.
D
D
Ehlers
Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany.|Institute of Applied Physics, Academy of Sciences of Moldova, MD 2028, Chisinau, Republica Moldova.
V
V
Tsurkan
Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg, Germany.
A
A
Loidl