Half-Metallicity in Triangulene-based Superatomic Graphene

TL;DR

This paper reports the synthesis and characterization of a phosphorus-doped triangulene-based superatomic graphene that exhibits intrinsic 2D half-metallic ferromagnetism, advancing the development of spintronic devices.

Contribution

It presents the first bottom-up synthesis of a superatomic graphene with half-metallic properties, combining experimental and theoretical analysis.

Findings

Demonstrated half-metallic ferromagnetism in superatomic graphene

Revealed spin-polarized bands originating from p$_x,_y$ orbitals

Validated experimental results with density functional theory simulations

Abstract

The discovery of two-dimensional (2D) magnets has opened up new possibilities for miniaturizing spintronic devices to the monolayer limit. 2D half-metals, capable of conducting fully spin-polarized currents when spin-orbit coupling is minimal, provide a key advantage in improving device performance. Extensive theoretical research has been carried out to discover 2D half-metals, yet their realization remains elusive. Here we report the bottom-up synthesis of superatomic graphene and the demonstration of its half-metallic properties. The produced graphene half-metal is fabricated through an on-surface synthetic approach with phosphorus-doped triangulene as its building block. Scanning tunneling microscopy measurements reveal its metallic band structures and identify its ferromagnetism through magnon excitation under varying magnetic fields. Density functional theory simulations accurately capture its half-metallic characteristics, uncovering the origin of spin-polarized bands from the p$_x,_y$-like orbital of superatomic graphene. Our work demonstrates intrinsic 2D carbon magnetism, paving the way for harnessing its advantages in spintronics.