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Abstract Realization of large effective phonon magnetic moment in monolayer MoS₂has established an important route for exploring intriguing magnetic phenomena in a nonmagnetic material. The sizable coupling between the orbital transition and the circularly polarized phonon results in the large effective phonon magnetic moment. In this work, using magneto-Raman spectroscopy, we investigate substitutional doping of magnetic atoms as a tuning knob of the electronic and phononic properties of MoS₂. We show that Fe-doping polarizes the spin of the conduction bands and introduces a localized Fe band underneath the conduction band. As a result, an additional orbital transition between the Mo 4dand Fe 3dstates emerges, producing an orbital-phonon hybridized mode at 283 cm⁻¹. Our magnetic field dependent measurements demonstrate that this new mode carries 2.8 ${\mu }_{\mathrm{B}}$effective phonon magnetic moment, which is comparable to that of the undoped MoS₂. Moreover, even though a long-range magnetic order is absent in Fe-doped MoS₂, the local magnetic moment of Fe modifies the nature of the spin fluctuation, producing monotonically increasing quasielastic scattering spectral weight as temperature decreases. Our results highlight two-dimensional dilute magnetic semiconductors synthesized by substitutional doping as a promising material platform to manipulate the phonon magnetic moment through orbital-phonon coupling. 

Non-collinear spin texture has attracted great attention since it provides an important probe of the interaction between electron and topological spin textures. While it has been widely reported in chiral magnets, oxide heterostructures, and hybrid systems such as ferromagnet/heavy metal and ferromagnet/topological insulators, the study of non-collinear spin texture in two-dimensional (2D) van der Waals (vdW) dilute magnetic semiconductor (DMS) monolayers is relatively lacking, hindering the understanding at the atomically thin scale. Here, we probe the temperature-dependent antisymmetric humps in Hall resistivity by utilizing the proximity coupling of Fe-doped monolayer WSe2 (Fe:WSe2) synthesized using chemical vapor deposition on a Pt Hall bar. Multiple characterization methods were employed to demonstrate that Fe atoms substitutionally replace W atoms, making a 2D vdW DMS at room temperature. Distinct from the intrinsic anomalous Hall effect, we found the transverse Hall resistivity of Fe:WSe2 displaying two additional antisymmetric peak features in the temperature-dependent measurements. These peaks are attributed to the magnetic features at the Fe:WSe2 and Pt interface. Our work shows that a DMS synthesized from 2D vdW transition metal dichalcogenides is promising for realizing magnetic and spintronic applications. 

Abstract The ability to modulate optical and electrical properties of two-dimensional (2D) semiconductors has sparked considerable interest in transition metal dichalcogenides (TMDs). Herein, we introduce a facile strategy for modulating optoelectronic properties of monolayer MoSe₂with external light. Photochromic diarylethene (DAE) molecules formed a 2-nm-thick uniform layer on MoSe₂, switching between its closed- and open-form isomers under UV and visible irradiation, respectively. We have discovered that the closed DAE conformation under UV has its lowest unoccupied molecular orbital energy level lower than the conduction band minimum of MoSe₂, which facilitates photoinduced charge separation at the hybrid interface and quenches photoluminescence (PL) from monolayer flakes. In contrast, open isomers under visible light prevent photoexcited electron transfer from MoSe₂to DAE, thus retaining PL emission properties. Alternating UV and visible light repeatedly show a dynamic modulation of optoelectronic signatures of MoSe₂. Conductive atomic force microscopy and Kelvin probe force microscopy also reveal an increase in conductivity and work function of MoSe₂/DAE with photoswitched closed-form DAE. These results may open new opportunities for designing new phototransistors and other 2D optoelectronic devices.