Magnetostriction of helimagnets in the skyrmion crystal phase

Abstract

We solve the magnetostriction strains for B20 helimagnets in the skyrmion crystal phase. By taking MnSi as an example, we reproduce its temperature-magnetic field (T-B) phase diagrams within a thermodynamic potential incorporating magnetoelastic interactions. The calculation shows that the normal strain ϵ 33 undergoes a sudden jump through a conical-skyrmion phase transition at any temperature. The corresponding experimental measurements for MnSi agree quantitatively well with the calculation.