Band curvature effects on quantum transport of spin-1 chiral fermion systems

We theoretically investigate the quantum transport properties of three-dimensional spin-1 chiral fermion systems with a curved trivial band. In the multiband system with two distinct characters---a linear Dirac band and a quadratic trivial band---the hybridization induced by impurity effects leads to pronounced energy and temperature dependences in the electrical conductivity. We show that the conductivity is suppressed by the trivial band in the low-energy regime near the threefold degenerate point and enhanced in the band-crossing point of the Dirac and trivial bands. These results are derived using the self-consistent Born approximation within the framework of linear response theory.