Proximity Effect in the Heterostructures with 2D Magnetic Materials

Since the discovery of 2D magnetism in monolayer FePS₃, CrI_3, and CrGeTe₃ in 2017, 2D van der Waals magnetic systems have been intensively studied because of their importance in fundamental physics and prospective applications in low power devices. In particular, van der Waals heterostructures containing 2D magnetic materials have offered a new platform for studying the manipulation of 2D magnetism which is crucial for the development of high-performance devices. In this presentation, we study the heterostructures built by chromium trihalides and molybdenum dichalcogenides MoSe₂(MoTe₂) using first-principle calculation. The low lattice mismatch strain of the resulting heterostructures enables us to study the proximity effect in the interface without the influence of many structural variations of component materials. We also studied the trilayer structure in which molybdenum dichalcogenides is sandwiched by two magnetic chromium trihalides. The change of magnetic properties of component materials upon assembling them together is investigated. Given the fact that the intralayer magnetic coupling in semiconducting chromium trihalides and interlayer magnetic coupling in vdW heterostructures is dominated by the superexchange mechanism, the results are discussed based on superexchange theory. In addition, MoSe₂ can become magnetic if Mo vacancy is present. The interplay between defect-induced magnetism and magnetic proximity effect can provide more fruitful physics. The study of the interface between 2D materials is vital since it is inevitably present in the real device.