Tunable valley splitting in two-dimensional CrBr 3 /VSe 2 van der Waals heterostructure under strains and electric fields

• Published in: Journal of physics. Condensed matter 2023-11, Vol.35 (45), p.455502
• Main Authors: Liang, Xuesong, Sun, Jin, Yu, Zhizhou
• Format: Article
• Language: English
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/acee3f

Valleytronics opens up fascinating opportunities for using the valley degree of freedom in information storage and quantum computation. Here, based on the first-principles calculations, we investigate the effects of biaxial strains and electric fields on the magnetic, electronic, and valleytronic properties of two-dimensional CrBr /VSe van der Waals heterostructure consisting of two ferromagnetic monolayers. An interlayer magnetic phase transition from parallel to antiparallel is found when a compressive strain exceeds -2% or a tensile strain exceeds 4% is applied, while the interlayer magnetic configuration remains parallel under perpendicular electric fields. The valley splitting in the conduction bands is significantly enhanced by a compressive strain or an electric field pointing from the VSe to the CrBr layer. Specifically, a large valley splitting about 30.8 meV is obtained in the system with antiparallel interlayer magnetic under a compressive strain of -4%, which is more than three times that of pristine CrBr /VSe heterostructure. Our findings provide new insights into the future valleytronic applications for two-dimensional magnetic van der Waals heterostructures.