Topological Dirac Semimetal BaAuSb

Dirac semimetals feature Dirac cones with topologically non-trivial states in the bulk that are protected by crystalline symmetries. They attract considerable attention due to rich quantum states and properties of interest, such as high Fermi velocities, mobility and small effective masses. In my talk I will show that ternary intermetallic BaAuSb crystal hosts both trivial and non-trivial topological Dirac states in the bulk. The non-trivial Fermi surface pocket at the Brillouin zone center is characterized with only few hundredths of the bare electron mass and with very high mobility. All parts of Fermi surface detected by quantum oscillations, topologically trivial or non-trivial have carriers with unusually high Fermi velocities and small masses.