Interplay between spin proximity effect and charge-dependent exciton dynamics in MoSe2/CrBr3 van der Waals heterostructures
Year: 2020
Type: article
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 MoSe 2 and CrBr 3 in photoluminescence, whereby the valley polarization of the MoSe 2 trion state conforms closely to the local CrBr 3 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 MoSe 2 as a promising candidate to optically interface with exotic spin textures in van der Waals structures.
Source: Nature Communications
Authors: T. P. Lyons, D. Gillard, A. Molina-Sánchez, A. Misra, F. Withers, P. S. Keatley, A. Kozikov, T. Taniguchi, K. Watanabe, K. S. Novoselov, J. Fernández-Rossier, A. I. Tartakovskii
Institutions: University of Sheffield, QuantaLab, International Iberian Nanotechnology Laboratory, Indian Institute of Technology Madras, University of Manchester, University of Exeter, National Institute for Materials Science, National University of Singapore, Chongqing 2D Materials Institute (China)
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $5,380
Funders: Graphene Flagship, Royal Society, Ministry of Education, Culture, Sports, Science and Technology, Generalitat Valenciana, Universitat de València, Barcelona Supercomputing Center, Engineering and Physical Sciences Research Council, Fundação para a Ciência e a Tecnologia, Core Research for Evolutional Science and Technology
Awards: G1274295419, G1958285767, G2115222242, DTP 2018-19 University of Sheffield, G2457300166, Microcavity polaritons in atomically thin semiconductors and heterostructures: many-body and nonlinear phenomena, Engineering van der Waals heterostructures: from atomic level layer-by-layer assembly to printable innovative devices, G2964576412, G3094178074, Light-matter interactions and quantum photonics in nano-scale semiconductor structures and devices, G3510308925, G369169853, G4008553048, G5138642760, G5166783610, G5454278309, G6343040030, G6623722071, G6635537352, Van der Waals Heterostructures of 2D Materials, G7123686865, EXTREMAG: an Exeter-based Time Resolved Magnetism Facility, Semicondutores magnéticos bidimensionais, G7879866177, G8430280503
OpenAlex ID: W3036067411