Abstract

Semiconducting ferromagnet-nonmagnet interfaces in van der Waals heterostructures present a unique opportunity to investigate magnetic proximity interactions dependent upon a multitude of phenomena including valley and layer pseudospins, moiré periodicity, or exceptionally strong Coulomb binding. Here, we report a charge-state dependency of the magnetic proximity effects between MoSe2 and CrBr3 in photoluminescence, whereby the valley polarization of the MoSe2 trion state conforms closely to the local CrBr3 magnetization, while the neutral exciton state remains insensitive to the ferromagnet. We attribute this to spin-dependent interlayer charge transfer occurring on timescales between the exciton and trion radiative lifetimes. Going further, we uncover by both the magneto-optical Kerr effect and photoluminescence a domain-like spatial topography of contrasting valley polarization, which we infer to be labyrinthine or otherwise highly intricate, with features smaller than 400 nm corresponding to our optical resolution. Our findings offer a unique insight into the interplay between short-lived valley excitons and spin-dependent interlayer tunneling, while also highlighting MoSe2 as a promising candidate to optically interface with exotic spin textures in van der Waals structures.

One advantage of van der Waals materials is the ability to combine different materials in layers to form new heterostructures. Here, the authors investigate heterostructures of CrBr3 and MoSe2, and find that the ferromagnetism of CrBr3 enhances the valley dependent optical response of the MoSe2.

Details

Title
Interplay between spin proximity effect and charge-dependent exciton dynamics in MoSe2/CrBr3 van der Waals heterostructures
Author
Lyons, T P 1   VIAFID ORCID Logo  ; Gillard, D 1   VIAFID ORCID Logo  ; Molina-Sánchez, A 2   VIAFID ORCID Logo  ; Misra, A 3 ; Withers, F 4   VIAFID ORCID Logo  ; Keatley, P S 4 ; Kozikov, A 5 ; Taniguchi, T 6   VIAFID ORCID Logo  ; Watanabe, K 6   VIAFID ORCID Logo  ; Novoselov, K S 7 ; Fernández-Rossier, J 2 ; Tartakovskii, A I 1   VIAFID ORCID Logo 

 The University of Sheffield, Department of Physics and Astronomy, Sheffield, UK (GRID:grid.11835.3e) (ISNI:0000 0004 1936 9262) 
 International Iberian Nanotechnology Laboratory, QuantaLab, Braga, Portugal (GRID:grid.420330.6) (ISNI:0000 0004 0521 6935) 
 The University of Manchester, School of Physics and Astronomy, Manchester, UK (GRID:grid.5379.8) (ISNI:0000000121662407); Indian Institute of Technology Madras (IIT Madras), Department of Physics, Chennai, India (GRID:grid.417969.4) (ISNI:0000 0001 2315 1926) 
 University of Exeter, Department of Physics and Astronomy, Exeter, UK (GRID:grid.8391.3) (ISNI:0000 0004 1936 8024) 
 The University of Manchester, School of Physics and Astronomy, Manchester, UK (GRID:grid.5379.8) (ISNI:0000000121662407) 
 National Institute for Materials Science, Tsukuba, Japan (GRID:grid.21941.3f) (ISNI:0000 0001 0789 6880) 
 The University of Manchester, School of Physics and Astronomy, Manchester, UK (GRID:grid.5379.8) (ISNI:0000000121662407); National University of Singapore, Centre for Advanced 2D Materials, Singapore, Singapore (GRID:grid.4280.e) (ISNI:0000 0001 2180 6431); Liangjiang New Area, Chongqing 2D Materials Institute, Chongqing, China (GRID:grid.4280.e) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2473271361
Copyright
© The Author(s) 2020. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.