Emergent phenomena of magnetic skyrmion and large DM interaction in perovskite manganite La0.8Sr0.2MnO3

Magnetic skyrmions, being one of the most promising candidates for the next generation memory-type application due to their nanometer-size and efficient current-driven dynamics, are mainly found and studied in alloy helimagnets in which the spin-orbit coupling induced by Dzyaloshinskii-Moriya interaction (DMI) enables noncollinear spin alignment and skyrmion formation. In this paper, we report a possible finding of skyrmions crystal near room-temperature in centrosymmetric structures perovskite manganite La0.8Sr0.2MnO3 (LSMO). Based on the measurements of isothermal magnetization around the Curie temperature (similar to 298 K), an unusual magnetic behavior of a discontinuous magnetization was observed and existed only at moderate magnetic field region together with a narrow temperature range from 306 to 290 K. Apart from this range, all curves return to conventional magnetic behavior of continuous change with external magnetic field. This characteristic has been frequently observed in some reported helimagnets (such as FeGe, MnSi), implying the possible existence of skyrmions crystal in LSMO. To further unveil the physical origin and underlying mechanisms, we performed the first-principles calculation for LSMO compound and a large DMI (Delta E-DMI = 13.46 meV, d(1) = 1.68 meV) was found to exists at the interface of LaMnO3/SrMnO3 layers. This result not only supports our experimental findings in the present composition but also is consistent with the formation mechanism of magnetic skyrmions.