Morpurgo, Alberto
Date: Thursday, January 28, 2021
Time: 10:00
Place: scheduled Zoom meeting
Host: Klaus Ensslin
2D Magnetic Materials
Alberto Morpurgo
University of Geneva
In this talk, I will give a short introduction to research on 2D magnetic materials and heterostructures. After a short introduction of the physical systems and of the general questions investigated in this domain of research, I will then move to present results obtained in my group on atomically thin multilayers of different antiferromagnetic semiconductors such as CrI3, CrCl3 (layered antiferromagnets) and MnPS3 (antiferromagnetic within individual layers). We use these layers to form tunnel barriers and reveal many interesting phenomena in the measurement of their tunneling resistance as a function of temperature and magnetic field. Examples include a giant tunneling magnetoresistance in CrI3, a nearly complete characterization of the magnetic properties of CrCl3 multilayers, and the observation of a spin-flop transition in MnPS3 persisting to the ultimate thickness of an individual monolayer. An important result of this work is that measurements of the temperature and magnetic field dependence of the tunneling magnetoresistance allow the phase diagram of 2D magnetic semiconductors to be established, something impossible to do with most conventional experimental techniques, not sufficiently sensitive when used on atomically thin layers. If time allows, I will also briefly mention work that we did on metallic 2D magnetic materials such as Cr1/3NbS2 (a helical magnet) or Co1/3NbS2 (an antiferromagnet with exhibiting an anomalous Hall conductance of 0.6 e2/h per layer), which exhibit interesting topological phenomena.