Sn*

The interplay between frustrated magnetism and itinerant electrons can give rise to topogical non-trivial properties such as anomalous Hall and Nernest effects in Mn₃Sn. Denisty functional thoery shows Weyl points close to Fermi energy are responsible for anomalous transport properties and can be controled by magnetism via spin-orbit coupling.

In this talk, I will present our neutron diffraction results at various temperatures and magnetic fields to understand the magnetic structure of Mn₃Sn in different magnetic phases. With vertical magnet and polarized neutron beam, we are able to clear the ambiguity in previous works and establish the exact k=0 anti-chiral spin structure at room temperature. For the incommensurate phase, the relation between ordering vectors and temperature was investigated and a refined mangetic structure at 250K will be presentated. At the end of this talk, the orgin of the incommensurabilties will be discussed with a proposed Hamiltonian.