Van der Waals Engineering of Ferromagnetic Semiconductor Heterostructures for Spin and Valleytronics

Abstract

The integration of magnetic material with semiconductors has been fertile ground for fundamental science as well as of great practical interest toward the seamless integration of information processing and storage. Here we create van der Waals heterostructures formed by an ultrathin ferromagnetic semiconductor CrI3 and a monolayer of WSe2. We observe unprecedented control of the spin and valley pseudospin in WSe2, where we detect a large magnetic exchange field of nearly 13 T and rapid switching of the WSe2 valley splitting and polarization via flipping of the CrI3 magnetization. The WSe2 photoluminescence intensity strongly depends on the relative alignment between photo-excited spins in WSe2 and the CrI3 magnetization, due to ultrafast spin-dependent charge hopping across the heterostructure interface. The photoluminescence detection of valley pseudospin provides a simple and sensitive method to probe the intriguing domain dynamics in the ultrathin magnet, as well as the rich spin interactions within the heterostructure.

Supplementary Materials included. To appear in Science Advances

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Cited by in corpus (10)

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• Layer-Resolved Magnetic Proximity Effect in van der Waals Heterostructures
• Gate-tunable spin waves in antiferromagnetic atomic bilayers
• Magnetic critical behavior of the van der Waals Fe5GeTe2 crystal with near room temperature ferromagnetism
• Magnetic proximity and nonreciprocal current switching in a monolayer WTe2 helical edge
• Observation of the polaronic character of excitons in a two-dimensional semiconducting magnet $\mathrm{Cr}{\mathrm{I}}_3$
• Asymmetric magnetic proximity interactions in MoSe${}_2$/CrBr${}_3$ van der Waals heterostructures
• Enhanced coercivity and emergence of spin cluster glass state in 2D ferromagnetic material Fe3GeTe2