Magnetic Proximity Effects in van der Waals Heterostructures

Abstract

Motivated by the recent discovery of 2D materials with ferromagnetic order and the continuous advances in the fabrication of artificial van der Waals heterostructures, the experimental work carried out in this master thesis focuses on proximity-induced magnetism in high spin-orbit layered materials. In particular, we have investigated magneto-transport and anomalous Hall effects in the van der Waals system WTe2/CGT. This is the preliminary step towards the realization of the QAHE, which requires the co-integration of monolayer WTe2 with a perpendicular magnetized 2D ferromagnet. Our experiments show that AHE is present on our samples, but this key observation is not a definitive proof of proximity-induced magnetism, but due to shunting of the electrical current to the CGT layer with an increased conductivity attributed to doping caused by thermal annealing. We have observed that the doping is also linked to an enhanced anisotropy and Curie temperature of CGT. The findings claim for a thorough revision of recent reports of the AHE induced by CGT in adjacent high spin-orbit materials.