Dirac fermions in half-metallic ferromagnetic mixed Cr$_{1\textrm{-}x}$M$_x$PSe$_3$ monolayers

TL;DR

This study predicts that alloyed CrPSe3 monolayers can host high-mobility Dirac fermions with ferromagnetic order, making them promising for spintronics.

Contribution

It demonstrates the emergence of Dirac fermions in mixed CrPSe3 monolayers with ferromagnetic properties using DFT and tight-binding methods.

Findings

Presence of Dirac cones at Fermi energy in mixed monolayers.

High Fermi velocities indicating high mobility.

Potential for spintronics applications due to ferromagnetism and Dirac fermions.

Abstract

The electronic and magnetic properties of pristine CrPSe$_3$ and mixed Cr$_{1\textrm{-}x}$M$_x$PSe$_3$ (M = Zn, Cd, Hg) monolayers were studied using density functional theory including an on-site Coulomb term (DFT$+U$) and tight-binding approach (TBA). While pristine CrPSe$_3$ monolayer has an antiferromagnetic (AFM) ground state, its alloying with MPSe$_3$ may give rise to half-metallic ferromagnet (HMF) with high Curie temperature. The resulting monolayers demonstrate single-spin Dirac cones of mainly Cr-$d$ character located in the first Brillouin zone directly at the Fermi energy. The calculated Fermi velocities of Dirac fermions indicate very high mobility in mixed Cr$_{1\textrm{-}x}$M$_x$PSe$_3$ monolayers, that makes this material appealing for low-dimensional spintronics applications.