Surface Versus Bulk Dirac States Tuning in a Three-Dimensional Topological Dirac Semimetal

Understand

Recently, crystalline-symmetry-protected three-dimensional (3D) bulk Dirac semimetal phase has been experimentally identified in a stoichiometric high-mobility compound, Cd3As2.

• The Dirac state observed in Cd3As2 has been attributed to originate mostly from the bulk state while calculations show that the bulk and surface states overlap over the entire Dirac dispersion energy range.
• In this study, we unambiguously reveal doping induced evolution of the ground state of surface and bulk electron dynamics in a 3D Dirac semimetal.
• We develop a systematic technique to isolate the surface and bulk states in Cd3As2, by simultaneously utilizing angle-resolved photoemission spectroscopy (ARPES) and in-situ surface deposition.