Electron-hole asymmetry, Dirac fermions, and quantum magnetoresistance inBaMnBi2

Here, we report two-dimensional quantum transport and Dirac fermions in BaMnBi₂ single crystals. BaMnBi₂ is a layered bad metal with highly anisotropic conductivity and magnetic order below 290 K. Magnetotransport properties, nonzero Berry phase, small cyclotron mass, and the first-principles band structure calculations indicate the presence of Dirac fermions in Bi square nets. Quantum oscillations in the Hall channel suggest the presence of both electron and hole pockets, whereas Dirac and parabolic states coexist at the Fermi level.