Spontaneous valley polarization in 2D organometallic lattice

TL;DR

This paper demonstrates the existence of spontaneous valley polarization in 2D organometallic lattices, expanding the scope of ferrovalley materials beyond inorganic systems and highlighting their potential for valleytronic applications.

Contribution

It introduces a new class of 2D organometallic ferrovalley materials with out-of-plane magnetization, identified through theoretical modeling and high-throughput calculations.

Findings

Ideal spontaneous valley polarization found in 2D organometallic lattices

Twelve promising candidate materials identified

Materials exhibit robust out-of-plane magnetization and potential for anomalous valley Hall effect

Abstract

2D ferrovalley materials that exhibit spontaneous valley polarization are both fundamentally intriguing and practically appealing to be used in valleytronic devices. Usually, the research on 2D ferrovalley materials is mainly focused on inorganic systems, severely suffering from in-plane magnetization. Here, we alternatively show by kp model analysis and high-throughput first-principles calculations that ideal spontaneous valley polarization is present in 2D organometallic lattice. We explore the design principle for organic 2D ferrovalley materials composed of (quasi-)planer molecules and transition-metal atoms in hexagonal lattice, and identify twelve promising candidates. These systems have a ferromagnetic or antiferromagnetic semiconducting state, and importantly they exhibit robust out-of-plane magnetization. The interplay between spin and valley, together with strong spin-orbit coupling of transition-metal atoms, guarantee the spontaneous valley polarization in these systems, facilitating the anomalous valley Hall effect. Our findings significantly broaden the scientific and technological impact of ferrovalley physics.