Bilayer CrI<sub>3</sub> Ground State Revealed by Layer-sensitive Magnetic Sensor
ORAL
Abstract
The recent identification of 2D magnetic CrI3 adds a new building block to the family of 2D materials. While its monolayer was proven to be an intrinsic ferromagnetic insulator, its bilayer intriguingly exhibits vanishing magnetization. This implies a layered-antiferromagnetic spin arrangement, i.e. individual monolayers are ferromagnetic while the interlayer coupling is antiferromagnetic. Therefore, a probe to resolve the magnetization of individual monolayers is needed to reveal the bilayer CrI3 ground state. Here we report magneto-optical spectroscopy studies on heterostructures of monolayer WSe2 and bilayer CrI3. Using the WSe2 valley exciton photoluminescence, we achieve a layer-specific probe of the magnetization via proximity coupling of the WSe2 to the CrI3. We then employ magnetic circular dichroism to correlate with the total magnetization state of bilayer. Our results reveal that bilayer CrI3 indeed has a layered antiferromagnetic configuration. We also reveal a spatially dependent coercivity phenomenon and discuss possible mechanisms.
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Presenters
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Ding Zhong
- University of Washington