TY - JOUR
T1 - Towards control of the size and helicity of skyrmions in helimagnetic alloys by spin-orbit coupling
AU - Shibata, K.
AU - Yu, X. Z.
AU - Hara, T.
AU - Morikawa, D.
AU - Kanazawa, N.
AU - Kimoto, K.
AU - Ishiwata, S.
AU - Matsui, Y.
AU - Tokura, Y.
PY - 2013/10
Y1 - 2013/10
N2 - Chirality - that is, left- or right-handedness - is an important concept in a broad range of scientific areas. In condensed matter, chirality is found not only in molecular or crystal forms, but also in magnetic structures. A magnetic skyrmion1-8 is a topologically stable spin vortex structure, as observed in chiral-lattice helimagnets, and is one example of such a structure. The spin swirling direction (skyrmion helicity) should be closely related to the underlying lattice chirality via the relativistic spin-orbit coupling. Here, we report on the correlation between skyrmion helicity and crystal chirality in alloys of helimagnets Mn1-x Fex Ge with varying compositions by Lorentz transmission electron microscopy and convergent-beam electron diffraction over a broad range of compositions (x = 0.3-1.0). The skyrmion lattice constant shows non-monotonous variation with composition x, with a divergent behaviour around x = 0.8, where the correlation between magnetic helicity and crystal chirality changes sign. This originates from continuous variation of the spin-orbit coupling strength and its sign reversal in the metallic alloys as a function of x. Controllable spin-orbit coupling may offer a promising way to tune skyrmion size and helicity.
AB - Chirality - that is, left- or right-handedness - is an important concept in a broad range of scientific areas. In condensed matter, chirality is found not only in molecular or crystal forms, but also in magnetic structures. A magnetic skyrmion1-8 is a topologically stable spin vortex structure, as observed in chiral-lattice helimagnets, and is one example of such a structure. The spin swirling direction (skyrmion helicity) should be closely related to the underlying lattice chirality via the relativistic spin-orbit coupling. Here, we report on the correlation between skyrmion helicity and crystal chirality in alloys of helimagnets Mn1-x Fex Ge with varying compositions by Lorentz transmission electron microscopy and convergent-beam electron diffraction over a broad range of compositions (x = 0.3-1.0). The skyrmion lattice constant shows non-monotonous variation with composition x, with a divergent behaviour around x = 0.8, where the correlation between magnetic helicity and crystal chirality changes sign. This originates from continuous variation of the spin-orbit coupling strength and its sign reversal in the metallic alloys as a function of x. Controllable spin-orbit coupling may offer a promising way to tune skyrmion size and helicity.
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U2 - 10.1038/nnano.2013.174
DO - 10.1038/nnano.2013.174
M3 - Article
AN - SCOPUS:84885482460
SN - 1748-3387
VL - 8
SP - 723
EP - 728
JO - Nature Nanotechnology
JF - Nature Nanotechnology
IS - 10
ER -