Regulated magnetic anisotropy and charge density wave in uniformly fabricated Janus CrTeSe monolayer

TL;DR

This study presents a method to synthesize uniform Janus CrTeSe monolayers with tailored magnetic and electronic properties, revealing a charge density wave transition and altered magnetic anisotropy through experimental and theoretical analysis.

Contribution

The paper introduces a general fabrication technique for uniform Janus CrTeSe monolayers with high crystal quality and demonstrates their unique magnetic and electronic properties.

Findings

Janus CrTeSe exhibits a charge density wave transition.

Magnetic anisotropy is significantly altered in Janus CrTeSe.

High-quality large-area Janus monolayers are successfully fabricated.

Abstract

Two-dimensional materials with Janus structure host novel physical properties due to their inversional symmetry breaking. However, it remains elusive to synthesize Janus monolayer crystals with tailored long-range magnetic orders. Here, we have developed a general method to fabricate uniform Janus CrTeSe monolayers by selective selenization of preformed CrTe2 monolayers with molecular beam epitaxy. The uniform Janus structure of CrTeSe with high crystal quality is confirmed by high-resolution scanning transmission electron microscopy. Spin-polarized scanning tunneling microscopy/spectroscopy measurements unveil that the Janus CrTeSe undergoes a charge density wave (CDW) transition and a robust antiferromagnetic order. The magnetic anisotropy of CrTeSe is drastically altered compared to monolayer CrTe2 by the breaking symmetries induced from the Janus structure and the CDW transition, as is substantiated with first principles calculations. Our research achieves the construction of large-area Janus structures, and artificially tailors the electronic and magnetic properties of Janus systems at the two-dimensional limit.