Room‐Temperature Ferromagnetism of Single‐Layer MoS₂ Induced by Antiferromagnetic Proximity of Yttrium Iron Garnet

Abstract

Single‐layered MoS2 is a naturally stable material. Integrating spin, valley, and circularly polarized photons is an interesting endeavor to achieve advanced spin‐valleytronics. In this study, room‐temperature ferromagnetism in MoS2 induced by the magnetic proximity effect (MPE) of yttrium iron garnet (YIG) and the antiferromagnetic coupling at the interface is demonstrated. Insulating YIG without charge carriers is an excellent magnetic candidate featuring a long spin diffusion length and remarkable surface flatness, enabling long‐range magnetic interactions with MoS2. Spin‐resolved photoluminescence spectroscopy and magnetic circular dichroism (MCD) reveal that the spin‐polarized valleys of MoS2 can achieve sustained ferromagnetism even at room temperature. The bandgap‐sensitivity of MCD further demonstrates the extent of antiferromagnetic coupling between the MPE‐induced moments of MoS2 and YIG. This work provides a layer‐selected approach to study magnetic interactions/configurations in the YIG/MoS2 bilayer and highlights the role of MoS2 in achieving the MPE toward high temperature.

Enhanced Magnetism and Anomalous Hall Transport through Two-Dimensional Tungsten Disulfide Interfaces

“…Recently, two-dimensional transition metal dichalcogenides (2D-TMDs) have attracted a great deal of attention due to their extraordinary bandgap tunability, high optical sensitivity, strong spin orbit coupling, and low symmetry structure, making this a fascinating class of materials for spintronics, valleytronics, and spin caloritronics [ 1 , 2 , 3 , 4 ]. Spin degeneracy in momentum space at K and K′ valley facilitates controllable spin polarization as detected by the helicity dependence of optical techniques such as magnetic circular dichroism [ 5 ] (MCD) and polarization resolved photoluminescence (PL). To enhance valley polarization, various approaches such as defect engineering [ 6 ], chemical doping [ 7 ], electrical doping [ 8 ], and TMD/FM (FM = ferro/ferrimagnet) heterostructures [ 5 , 9 , 10 , 11 , 12 ] have been exploited.…”

“…Spin degeneracy in momentum space at K and K′ valley facilitates controllable spin polarization as detected by the helicity dependence of optical techniques such as magnetic circular dichroism [ 5 ] (MCD) and polarization resolved photoluminescence (PL). To enhance valley polarization, various approaches such as defect engineering [ 6 ], chemical doping [ 7 ], electrical doping [ 8 ], and TMD/FM (FM = ferro/ferrimagnet) heterostructures [ 5 , 9 , 10 , 11 , 12 ] have been exploited. Among these, TMD/FM heterostructures based on spin orbit coupling [ 13 ], charge transfer [ 9 , 14 ], and magnetic proximity effect [ 5 , 10 ] (MPE) are of topical interest.…”

“…To enhance valley polarization, various approaches such as defect engineering [ 6 ], chemical doping [ 7 ], electrical doping [ 8 ], and TMD/FM (FM = ferro/ferrimagnet) heterostructures [ 5 , 9 , 10 , 11 , 12 ] have been exploited. Among these, TMD/FM heterostructures based on spin orbit coupling [ 13 ], charge transfer [ 9 , 14 ], and magnetic proximity effect [ 5 , 10 ] (MPE) are of topical interest. The MPE, an interfacial magnetic phenomenon due to the exchange coupling based on interfacial orbital hybridization [ 15 ].…”

Strain-Modulated Magnetism in MoS2

“…Except for graphene, MoS 2 [ 17 , 18 , 19 , 20 , 21 ] has also attracted extensive attention. Interestingly, many experimental studies show that the defective MoS 2 nanostructures [ 18 , 19 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ] also exhibit FM.…”

Valley polarization of trions in monolayer MoSe$_2$ interfaced with bismuth iron garnet

“…Iron garnets have recently attracted attention as promising magnetic substrates for TMD-based heterostructures, in particular yttrium iron garnet (YIG) [16,17]. Beyond its unique spin properties enabling, for example, magnon-exciton coupling [18], this ferrimagnetic insulator with low surface roughness can significantly dope TMD monolayers when brought in contact, which boosts the oscillator strength of trions without significantly changing the quality of their optical response [19].…”