2. The concept of a skyrmion was introduced in 1961 in the context of nuclear physics [2] and in 1989, magnetic skyrmions were predicted [3] to occur as a result of the competition between the Heisenberg exchange energy and the Dzyaloshinskii-Moriya interaction. [4] We use the term "DMskyrmions" to refer to such objects.DM-skyrmions were found experimentally [5] in bulk MnSi in 2009. This prompted the recent intense research effort as

Previous observations of metastable magnetic skyrmions have shown that close to the equilibrium pocket the metastable state has a short lifetime, and therefore rapid cooling is required to generate a significant skyrmion population at low temperatures. Here, we report that the lifetime of metastable skyrmions in Cu2OSeO3 is extended by a factor of 50 with the introduction of only 2.5% zinc doping, allowing over 50% of the population to survive when field-cooling at a rate of just 1 K/min. Our systematic study suggests that the lifetime enhancement is due to the removal of spins by the nonmagnetic dopant, which entropically limits the number of skyrmion decay pathways. We expect that doping can be exploited to control the lifetime of the metastable SkL state in other chiral magnets, offering a method of engineering skyrmion materials towards application in future devices. arXiv:1809.02590v2 [cond-mat.str-el]

The GaV4S8−ySey (y = 0 to 8) family of materials have been synthesized in both polycrystalline and single crystal form, and their structural and magnetic properties thoroughly investigated. Each of these materials crystallizes in the F$$\bar{4}$$ 4 ˉ 3m space group at ambient temperature. However, in contrast to the end members GaV4S8 and GaV4Se8, that undergo a structural transition to the R3m space group at 42 and 41 K respectively, the solid solutions (y = 1 to 7) retain cubic symmetry down to 1.5 K. In zero applied field the end members of the family order ferromagnetically at 13 K (GaV4S8) and 18 K (GaV4Se8), while the intermediate compounds exhibit a spin-glass-like ground state. We demonstrate that the magnetic structure of GaV4S8 shows localization of spins on the V cations, indicating that a charge ordering mechanism drives the structural phase transition. We conclude that the observation of both structural and ferromagnetic transitions in the end members of the series in zero field is a prerequisite for the stabilization of a skyrmion phase, and discuss how the absence of these transitions in the y = 1 to 7 materials can be explained by their structural properties.