Quantum Transport Evidence for the Three-Dimensional Dirac Semimetal Phase in Cd3As2

We report the quantum transport properties of Cd₃As₂ single crystals in a magnetic field. A large linear quantum magnetoresistance is observed near room temperature. With decreasing temperature, the Shubnikov—de Haas oscillations appear in both the longitudinal resistance R_{x x} and the transverse Hall resistance R_{x y}. From the strong oscillatory component Δ R_{x x}, a linear dependence of the Landau index n on 1 /B is obtained, and it gives an n -axis intercept between 1 /2 and 5 /8 . This clearly reveals a nontrivial π Berry's phase, which is a distinguished feature of Dirac fermions. Our quantum transport results provide bulk evidence for the existence of a three-dimensional Dirac semimetal phase in Cd₃As₂ .