  An idea is proposed for realizing a fully spin-polarized Dirac semimetal in
frustrated itinerant magnets. We show that itinerant electrons on a triangular
lattice exhibit the Dirac cone dispersion with half-metallic behavior in the
presence of a three-sublattice ferrimagnetic order. The Dirac nodes have the
same structure as those of graphene. By variational calculation and Monte Carlo
simulation, we demonstrate that the ferrimagnetic order with the Dirac node
spontaneously emerges in a simple Kondo lattice model with Ising anisotropy.
The realization will be beneficial for spintronics as a candidate for
spin-current generator.
