Tunable quantum transport in topological semimetal candidates La_xSr_1-xMnSb₂

Abstract The magnetic semimetal SrMnSb 2 contains a nonsymmorphic crystal symmetry that could protect Dirac crossings, offering the coexistence of a quasi-two-dimensional characteristic, magnetic order and nontrivial topology in bulk single crystals. Here, we report the evolution of Fermi surfaces by probing quantum oscillations in the La x Sr 1- x MnSb 2 single crystals. Hall measurements reveal that the conduction process changes from a hole-dominated multiband nature to a single hole-band nature after La doping. Compared with parent-SrMnSb 2 , the Fermi surface corresponding to F α is slightly enlarged and the small Fermi surface corresponding to F γ appears with a tunable feature in La-doped crystals. The topological semimetal candidates La x Sr 1- x MnSb 2 provide a fine-tuning platform for potential applications in the future.