Exploring spin-canting in the Dirac semimetal, Ca_1-<i>x</i>Na<i>_x</i>MnBi₂,with neutron diffraction measurements_.

Recent optical and magnetic torque measurements of Ca_1-xNa_xMnBi₂ suggested that the observed anomalous behavior in their dc resistivity at temperatures below the antiferromagnetic transition is consistent with the canting of the Manganese ordered moments [1]. Spin canting in the 112 families of Dirac semimetals is interesting because it can lead to the type-II Weyl state as a consequence of time-reversal symmetry breaking. However, previously reported canting driven Weyl states in other members, such as YbMnBi₂ [1], are controversial and refuted by neutron diffraction measurements. To understand whether the spin-canting is behind the anomalous resistivity bump, we performed neutron diffraction measurements on two members of Ca_1-xNa_xMnBi₂, x = 0 and 0.05. I will discuss the observed superstructure peaks, which appear consistent with the resistivity bump, in the framework of the spin canting. The result is important because it suggests Ca_1-xNa_xMnBi₂ as a rare member of 112 Dirac semimetals with the possibility of type-II Weyl state. [1] R. Yang et. al PRL 124,137201 (2020).