Bi – a 3D Dirac semimetal

3D topological Dirac semimetals (TDS) such as Na₃Bi and Cd₃As₂ possess Dirac nodes located outside the time-reversal invariant momentum points in the Brillouin zone. Recent theoretical and experimental work shows that quantum confinement of 3D TDS can open a tunable bulk bandgap and give rise to thickness-dependent alternate transitions between trivial and quantum spin Hall insulator states. In this talk, we will present our results on ultra-thin growth of Na₃Bi films on insulating substrates using molecular beam epitaxy (MBE). We will also discuss our efforts towards angle-dependent high-field in-situ magnetotransport measurements on back-gated thin films of Na₃Bi.