Spin Chirality in Mn₃IrSi using Polarized Neutron Diffraction

Frustrated magnetic interactions within the materials create complex spin arrangements, providing an ideal platform to study spin states with nontrivial topology, such as magnetic skyrmions [1]. In this context, our study focuses on Mn₃IrSi. The crystal structure of Mn₃IrSi (P2₁3) is an ordered form of β-Mn (P4₁32/P4₃32) and exhibits a complex hyperkagome atomic arrangement [2]. Notably, the system exhibits antiferromagnetic ordering at ~ 230K. This transition is accompanied by a remarkable increase in electrical resistivity below T_N and a distinct λ-type anomaly in specific heat [3]. These observations provide compelling evidence for the possibility of a spin density wave or an antiferromagnetic gap at the Fermi surface in Mn₃IrSi, emphasizing the intricate interplay between its magnetic and electronic properties. As, the investigation of chirality in geometrically frustrated magnetic systems is of utmost importance due to its profound influence on emergent magnetic phenomena. Here, we utilized the polarized neutron scattering on the Mn₃IrSi crystal at zero field, revealing that this system exhibits mono-chiral with a left-handed proper screw-type magnetic modulation, which aligns with the non-centrosymmetric crystal structures.