Correlated electronic structure of the kagome metal Mn3Sn

Mn3Sn is a fascinating kagome metal exhibiting anomalous Hall effect, spin Hall effect, and anomalous Nernst effect. Using density functional theory plus dynamical mean-field theory (DFT + DMFT), we investigate the electronic structures of Mn3Sn in the paramagnetic and noncollinear antiferromagnetic (NAFM) states. In the paramagnetic state, Mn3Sn has intermediate electronic correlation strength and exhibits typical features of kagome metals including flat bands, Dirac points, and saddle points. In the NAFM state, DFT + DMFT calcu-lations reproduce well the experimental Mn magnetic moment and angle-resolved photoemission spectroscopy measurements. Electronic correlation shifts the bands around EF and moves the Weyl point between K and M points from -40 meV above EF in DFT calculations to -5 meV below EF, which can strongly enhance the anomalous Hall effect and chiral anomaly observed in Mn3Sn. More importantly, we find that the existence of the Weyl point along the K -M path depends strongly on the ordering pattern of the Mn moments in the NAFM state, which implies that the exotic properties arising from the Weyl points in Mn3Sn can be manipulated by tuning the ordering pattern of the Mn moments in the NAFM state.