Prediction of room-temperature two-dimensional $π$-electron half-metallic ferrimagnets

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Phillips, J., Henriques, J. C. G., Fernández-Rossier, J., Costa, A. T.
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917412647993344
author Phillips, J.
Henriques, J. C. G.
Fernández-Rossier, J.
Costa, A. T.
author_facet Phillips, J.
Henriques, J. C. G.
Fernández-Rossier, J.
Costa, A. T.
contents We propose a strategy to obtain conducting organic materials with fully spin-polarized Fermi surface, lying at a singular flat band, with antiferromagnetically coupled magnetic moments that reside in pi-orbitals of nanographenes. We consider a honeycomb crystal whose unit cell combines two different molecules with S=1/2: an Aza-3-Triangulene, a molecule with orbital degeneracy, and a 2-Triangulene. The analyzed system is half-metallic with a ferrimagnetic order, presenting a zero net total magnetic moment per unit cell. We combine density functional theory calculations with a Hubbard model Hamiltonian to compute the magnetic interactions, the bands, the intrinsic Anomalous Hall effect, and the collective spin excitations. We obtain very large intermolecular exchange couplings, in the range of 50 meV, which ensures room temperature stability. When the magnetization is off-plane, intrinsic spin orbit coupling in graphene opens up a topological gap that, despite being very small, leads to a quantized Hall conductance in the tens of mK range. Above 1 Kelvin, the system will behave like a half-metal with fully compensated magnetic moments, thereby combining two characteristics that make it ideal for spintronics applications.
format Preprint
id arxiv_https___arxiv_org_abs_2602_17489
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Prediction of room-temperature two-dimensional $π$-electron half-metallic ferrimagnets
Phillips, J.
Henriques, J. C. G.
Fernández-Rossier, J.
Costa, A. T.
Mesoscale and Nanoscale Physics
Materials Science
We propose a strategy to obtain conducting organic materials with fully spin-polarized Fermi surface, lying at a singular flat band, with antiferromagnetically coupled magnetic moments that reside in pi-orbitals of nanographenes. We consider a honeycomb crystal whose unit cell combines two different molecules with S=1/2: an Aza-3-Triangulene, a molecule with orbital degeneracy, and a 2-Triangulene. The analyzed system is half-metallic with a ferrimagnetic order, presenting a zero net total magnetic moment per unit cell. We combine density functional theory calculations with a Hubbard model Hamiltonian to compute the magnetic interactions, the bands, the intrinsic Anomalous Hall effect, and the collective spin excitations. We obtain very large intermolecular exchange couplings, in the range of 50 meV, which ensures room temperature stability. When the magnetization is off-plane, intrinsic spin orbit coupling in graphene opens up a topological gap that, despite being very small, leads to a quantized Hall conductance in the tens of mK range. Above 1 Kelvin, the system will behave like a half-metal with fully compensated magnetic moments, thereby combining two characteristics that make it ideal for spintronics applications.
title Prediction of room-temperature two-dimensional $π$-electron half-metallic ferrimagnets
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2602.17489