Half-metallic magnetization plateaux

TL;DR

This paper introduces a new interaction-based method to achieve half-metallic states in 2D electron systems, utilizing magnetic fields and density wave states to produce magnetization plateaux with potential applications in spintronics.

Contribution

It presents a novel route to realize half-metallic states through interaction-driven density wave locking, supported by analysis of the Hubbard model on a triangular lattice.

Findings

Half-metallic states can be induced by magnetic field tuning of spin densities.

Magnetization plateaux occur over finite magnetic field intervals.

The approach is demonstrated in the Hubbard model on a triangular lattice.

Abstract

We propose a novel interaction-based route to half-metal state for interacting electrons on two-dimensional lattices. Magnetic field applied parallel to the lattice is used to tune one of the spin densities to a particular commensurate with the lattice value in which the system spontaneously `locks in' via van Hove enhanced density wave state. Electrons of opposite spin polarization retain their metallic character and provide for the half-metal state which, in addition, supports magnetization plateau in a finite interval of external magnetic field. Similar half-metal state is realized in the finite-U Hubbard model on a triangular lattice at 1/3 of the maximum magnetization.