Landau index n plotted against 1/B for Cd₃As₂ single crystals.^[38] The closed circles denote the integer index (ΔR_xx valley), and the open circles indicate the half integer index (ΔR_xx peak). Two straight-line fittings extrapolate to 0.58 ± 0.01 and 0.56 ± 0.03, respectively, which is a strong evidence for the nontrivial π Berry’s phase of 3D Dirac fermions in Cd₃As₂.^[38]