Dirac semimetals have attracted a great deal of current interests due to their potential applications in topological quantum computing, low-energy electronic devices, and single photon detection in the microwave frequency range. Herein are results from analyzing the low magnetic (B) field weak-antilocalization behaviors in a Dirac semimetal Cd3As2 thin flake device. At high temperatures, the phase coherence length l (phi) first increases with decreasing temperature (T) and follows a power law dependence of l (phi) proportional to T (-0.4). Below similar to 3 K, l (phi) tends to saturate to a value of similar to 180 nm. Another fitting parameter alpha, which is associated with independent transport channels, displays a logarithmic temperature dependence for T > 3 K, but also tends to saturate below similar to 3 K. The saturation value, similar to 1.45, is very close to 1.5, indicating three independent electron transport channels, which we interpret as due to decoupling of both the top and bottom surfaces as well as the bulk. This result, to our knowledge, provides first evidence that the surfaces and bulk states can become decoupled in electronic transport in Dirac semimetal Cd3As2.
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