Alberto Morpurgo : Probing 2D Magnetic Materials with magnetotransport in field-effect transistors

The ability to exfoliate van der Waals crystals of magnetic compounds is giving access to a vast, unexplored family of two-dimensional magnetic materials, with a variety of different magnetic ground states. Most of these compounds are semiconductors that offer –besides the possibility to explore magnetism in highly controlled 2D crystals— a new playground to combine magnetic and semiconducting functionalities. In this talk I will discuss how magnetotransport experiments allow the investigation the magnetic phase diagram of 2D magnetic material down to the ultimate limit of individual monolayers, to reveal phenomena that are difficult –or cannot—be accessed with other existing experimental techniques. I will focus on two main topics: i) recent experiments on field effect transistors realized on exfoliated crystals of CrPS4 –ranging from relatively thick multilayers, to double-gated bilayers– in which single and double gating allows us to detect and control the effect of magnetism on the semiconducting band structure; ii) work on NiPS3 field-effect transistors, in which we are able to map the phase diagram of 2D intralayer antiferromagnetism down to individual monolayer, and observe the effect of different magnetic-anisotropy terms.