Abstract
Magnetic proximity effects are integral to manipulating spintronic1,2, superconducting3,4, excitonic5 and topological phenomena6–8 in heterostructures. These effects are highly sensitive to the interfacial electronic properties, such as electron wavefunction overlap and band alignment. The recent emergence of magnetic two-dimensional materials opens new possibilities for exploring proximity effects in van der Waals heterostructures9–12. In particular, atomically thin CrI3 exhibits layered antiferromagnetism, in which adjacent ferromagnetic monolayers are antiferromagnetically coupled9. Here we report a layer-resolved magnetic proximity effect in heterostructures formed by monolayer WSe2 and bi/trilayer CrI3. By controlling the individual layer magnetization in CrI3 with a magnetic field, we show that the spin-dependent charge transfer between WSe2 and CrI3 is dominated by the interfacial CrI3 layer, while the proximity exchange field is highly sensitive to the layered magnetic structure as a whole. In combination with reflective magnetic circular dichroism measurements, these properties allow the use of monolayer WSe2 as a spatially sensitive magnetic sensor to map out layered antiferromagnetic domain structures at zero magnetic field as well as antiferromagnetic/ferromagnetic domains at finite magnetic fields. Our work reveals a way to control proximity effects and probe interfacial magnetic order via van der Waals engineering13.
| Original language | English |
|---|---|
| Pages (from-to) | 187-191 |
| Number of pages | 5 |
| Journal | Nature Nanotechnology |
| Volume | 15 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 1 2020 |
Funding
We thank A. Lonescu and I. Wilson for assistance in sample fabrication. This work was mainly supported by the Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division (grant no. DE-SC0018171). The understanding of the magnetic proximity effect was partially supported by the Department of Energy Pro-QM EFRC (grant no. DE-SC0019443). Work at HKU was supported by the RGC of HKSAR (grant no. 17303518P). Work at ORNL (M.A.M.) was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by MEXT, Japan and CREST (grant no. JPMJCR15F3), JST. K.-M.C.F. and X.L. acknowledge support by a University of Washington Innovation Award. X.X. acknowledges support from the State of Washington funded Clean Energy Institute and from a Boeing Distinguished Professorship in Physics.