Squeezing the periodicity of Néel-type magnetic modulations by enhanced Dzyaloshinskii-Moriya interaction of 4d electrons

In polar magnets, such as GaV${}_4$S${}_8$, GaV${}_4$Se${}_8$ and VOSe${}_2$O${}_5$, modulated magnetic phases namely the cycloidal and the Néel-type skyrmion lattice states were identified over extended temperature ranges, even down to zero Kelvin. Our combined small-angle neutron scattering and magnetization study shows the robustness of the Néel-type magnetic modulations also against magnetic fields up to 2 T in the polar GaMo${}_4$S${}_8$. In addition to the large upper critical field, enhanced spin-orbit coupling stabilize cycloidal, Néel skyrmion lattice phases with sub-10 nm periodicity and a peculiar distribution of the magnetic modulation vectors. Moreover, we detected an additional single-q state not observed in any other polar magnets. Thus, our work demonstrates that non-centrosymmetric magnets with 4d and 5d electron systems may give rise to various highly compressed modulated states.