Efficient spin to charge current conversion in the 2D semiconductor MoS2 by spin pumping from yttrium iron garnet

Abstract

We report efficient spin to charge current conversion in the 2D transition metal dichalcogenide semiconductor MoS2 at room temperature. The spin current is generated by microwave-driven ferromagnetic resonance spin pumping in a film of the ferrimagnetic insulator yttrium iron garnet (YIG) in atomic contact with the MoS2 layer. The use of insulating YIG allows the observation of a field-symmetric voltage signal without the contamination of asymmetrical lines due to spin rectification effects observed in studies using metallic ferromagnets. The observed voltage is attributed to spin-to-charge current conversion based on the inverse Edelstein effect (IEE) made possible by the spin-momentum locking in the electron Fermi contours due to the Rashba field. The measured IEE coefficient is two orders of magnitude larger than in graphene and is comparable to or larger than the values reported for some metallic interfaces and for several topological insulators.

Enhanced Spin Seebeck Effect in Monolayer Tungsten Diselenide Due to Strong Spin Current Injection at Interface

“…The ML WSe 2 interlayer can enhance the spin-to-charge conversion at the Pt/YIG interface due to the large spin-orbit coupling (SOC) in WSe 2 , ultimately enhancing V LSSE . [13,27,28] Further, we measured the LSSE signal in Cu coated on a YIG/GGG substrate at 300 K. As shown in Figure S3, Supporting Information, no V LSSE signal was observed in the Cu film on the YIG/GGG substrate because of the small SOC of Cu compared with that of Pt. [29] To further confirm the enhancement of the LSSE signal by the ML WSe 2 interlayer between the Pt and YIG layers, we conducted an LSSE measurement on a differently prepared (i.e., CVD-grown) ML WSe 2 flake interlayer (Sample E) at 300 K. The ML WSe 2 flakes were wet-transferred onto the whole area of the YIG film (Figure 3d).…”

Compared Efficiencies of Conversions between Charge and Spin Current by Spin-Orbit Interactions in Two- and Three-Dimensional Systems

“…The situation would come back definitely at the advantage of a TI only if its sheet resistance amounts to only a few hundreds of ohms, and, of course, in the ideal situation with an insulating magnetic layer and no shunting effect. For instance, a relatively large IEE efficiency, λ IEE = 0.4 nm, has been reported using YIG/MoS 2 [43].…”

Van der Waals magnets: Wonder building blocks for two‐dimensional spintronics?

“…There have also been intensive efforts toward bilayer structures in which 2D materials are placed in intimate contact with magnetic insulators or 2D‐vdW magnets . In those cases, the magnetic proximity effect, spin‐orbit torque or spin pumping is utilized to spin‐polarize and/or valley‐polarize 2D materials or generate spin current for low‐power spintronic applications.…”

“…There have also been intensive efforts toward bilayer structures in which 2D materials are placed in intimate contact with magnetic insulators or 2D-vdW magnets. 111,114,[160][161][162][163][164][165] In those cases, the magnetic proximity effect, spin-orbit torque or spin pumping is utilized to spin-polarize and/or valleypolarize 2D materials or generate spin current for low-power spintronic applications. This aspect, particularly facilitated by the atomically sharp interfacial registry of 2D materials, has been reviewed in more detail elsewhere.…”