Melting of hexagonal Skyrmion states in chiral magnets

Skyrmions are spiral structures observed in thin films of certain mag-netic materials [1]. Of the phases allowed by the crystalline symmetries of these materials [2] only the hexagonally packed phases (SCh) has been observed. Here the melting of the SCh phase is investigated using Monte Carlo simulations. In addition to the usual measure of Skyrmion density chiral charge, a morphological measure is considered. In doing so it is shown that the low temperature reduction in chiral charge is associated with a change in Skyrmion profiles rather than Skyrmion destruction. At higher temperatures the loss of six fold symmetry is associated with the appearance of elongated Skyrmions that disrupt the hexagonal packing