3d Transition Metal Adsorption Induced Vally-polarized Anomalous Hall Effect in Germanene

TL;DR

This study demonstrates that adsorbing specific 3d transition metals on germanene induces a valley-polarized anomalous Hall effect, enabling potential applications in valleytronics and next-generation electronic devices.

Contribution

It reveals that Cr, Mn, or Co adsorption on germanene induces valley-polarized anomalous Hall effects, with tunable valley Hall voltage via Fermi energy shifts, advancing valleytronics.

Findings

Valley-polarized anomalous Hall effect observed in TM-germanene.

Finite valley Hall voltage detectable in nanoribbons.

Reversible valley Hall voltage achieved by Fermi level tuning.

Abstract

Based on DFT+U and Berry curvature calculations, we study the electronic structures and topological properties of 3d transition metal (TM) atom (from Ti to Co) adsorbed germanene (TM-germanene). We find that valley-polarized anomalous hall effect (VAHE) can be realized in germanene by adsorbing Cr, Mn, or Co atom on its surface. A finite valley hall voltage can be easily detected in its nanoribbon, which is important for valleytronics devices. Moreover, different valley-polarized current and even reversible valley Hall voltage can be archived by shifting the Fermi energy of the systems. Such versatile features of the systems show potential in next generation electronics devices.