Room Temperature Ferroelectricity, Ferromagnetism, and Anomalous Hall Effect in Half-metallic Monolayer CrTe

TL;DR

This paper reports that monolayer CrTe is a stable, room-temperature multiferroic material exhibiting ferroelectricity, ferromagnetism, and tunable anomalous Hall effect, promising for spintronics and ferroelectric applications.

Contribution

It demonstrates that monolayer CrTe is a stable, room-temperature multiferroic with coupled ferroelectricity and ferromagnetism, and tunable electronic properties, which is rare among 2D materials.

Findings

Monolayer CrTe is dynamically stable at room temperature.

CrTe exhibits ferromagnetism with significant in-plane anisotropy.

It shows large out-of-plane ferroelectric polarization and tunable anomalous Hall effect.

Abstract

Two-dimensional materials hosting ferroelectricity and ferromagnetism are crucial for low-power and high-speed information processing technologies. However, intrinsic 2D multiferroics in the monolayer limit are rare. Here, we demonstrate that monolayer CrTe, obtained by cleaving the [002] surface, is dynamically stable multiferroic at temperatures beyond room temperature. We show that it orders ferromagnetically with significant in-plane magnetocrystalline anisotropy, and it is a half-metal featuring a large half-metal gap. Remarkably, the broken inversion symmetry and buckled geometry of monolayer CrTe make it a ferroelectric with a large spontaneous out-of-plane polarization and significant magnetoelectric coupling. In addition, we demonstrate polarization or electric field-induced tunability of the anomalous Hall effect, accompanied by substantial bandstructure modulation. Our findings establish monolayer CrTe as a room-temperature multiferroic with great potential for applications in spintronics and ferroelectric devices.