Dirac half-metal in a triangular ferrimagnet

TL;DR

This paper proposes a new way to realize a fully spin-polarized Dirac semimetal in frustrated itinerant magnets, demonstrating that a specific magnetic order on a triangular lattice can produce graphene-like Dirac nodes with potential spintronics applications.

Contribution

It introduces a novel mechanism for realizing Dirac semimetals in frustrated magnetic systems via a ferrimagnetic order on a triangular lattice.

Findings

Dirac cone dispersion with half-metallic behavior observed in the model.

Ferrimagnetic order with Dirac nodes spontaneously emerges in the Kondo lattice model.

Potential application in spintronics as a spin-current generator.

Abstract

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.