The de Hass-van Alphen quantum oscillations in a three-dimensional Dirac semimetal TiSb2

Characterization of the Fermi surface of high-quality crystalline TiSb2 by de Hass-van Alphen measurement reveals nontrivial topological properties. Moreover, our analysis of the quantum oscillation frequencies associated with nonzero Berry phase when the magnetic field is parallel to both the ab-plane and c-axis of TiSb2 finds that the Fermi surface topology has a three-dimensional feature. The results are supported by first-principle calculations which reveal a symmetry-protected Dirac point along the Gamma-Z high symmetry line near the Fermi level. On the (001) surface, the bulk Dirac points are found to project onto the point with nontrivial surface states. Our finding will substantially enrich the family of 3D Dirac semimetals which are useful for topological applications.