Magnetic Weyl semimetal emerging from non-magnetic doping

The investigation of new mechanism that could result in a controllable ferromagnetic (FM) component in a Weyl semimetal in the absence of external fields is of utmost importance. Here we report the enhancement of FM component induced by non-magnetic doping and the emergence of magnetic Weyl states in SrMn_1-xZn_xSb₂. SrZnSb₂ results non-magnetic, while both SrMnSb₂ and SrZn_0.25Mn_0.75Sb₂ are magnetic with strong spin-orbit coupling due to the presence of Mn. SrMnSb₂shows an AFM behavior caused by the inverse spin polarization of neighbors Mn. On the contrary, the substitution of one Mn with Zn induces a total magnetization on SrZn_0.25Mn_0.75Sb₂, turning the system on a ferromagnet. From the computed band structures and fermi surface, we deduce a nature of semimetal, small-gap insulator and Weyl semimetal for SrZnSb₂, SrMnSb₂ and SrZn_0.25Mn_0.75Sb₂ respectively. Further, SrMn_1-xZn_xSb₂ (x = 0.065 and 0.262) were also synthetized and characterized. Non-trivial de-Haas van Alphen and Shubnikov – de Haas oscillations were measured, reinforcing the theoretical finding of Weyl semimetal nature for SrMn_1-xZn_xSb₂.