Large Spin-To-Charge Conversion at the Two-Dimensional Interface of Transition-Metal Dichalcogenides and Permalloy

Abstract

Spin-to-charge conversion is an essential requirement for the implementation of spintronic devices. Recently, monolayers of semiconducting transition metal dichalcogenides (TMDs) have attracted considerable interest for spin-to-charge conversion due to their high spin-orbit coupling and lack of inversion symmetry in their crystal structure. However, reports of direct measurement of spin-to-charge conversion at TMD-based interfaces are very much limited. Here, we report on the room temperature observation of a large spin-to-charge conversion arising from the interface of Ni80Fe20 (Py) and four distinct large area (∼ 5 × 2 mm 2 ) monolayer (ML) TMDs namely, MoS2, MoSe2, WS2, and WSe2. We show that both spin mixing conductance and the Rashba efficiency parameter (λIREE) scales with the spin-orbit coupling strength of the ML TMD layers. The λIREE parameter is found to range between −0.54 and −0.76 nm for the four monolayer TMDs, demonstrating a large spin-tocharge conversion. Our findings reveal that TMD/ferromagnet interface can be used for efficient generation and detection of spin current, opening new opportunities for novel spintronic devices.

High temperature stability in few atomic layer MoS2 based thin film heterostructures: structural, static and dynamic magnetization properties

“…69,72,73 A similar phenomenon i.e., complete spin angular momentum relaxation in MLs for TMDs was also reported in previous reports. [15][16][17] This ISOC is also well known to provide the most dominating role in spin relaxation for 2D NM materials. [74][75][76][77] However, in the case of 3D NMs such as HMs (Pt, W, Ta, and so on), the spin relaxation occurs in the bulk of the HM layer via symmetry independent bulk SOC and has exponential dependence on the NM material thickness.…”

“…It is experimentally demonstrated that the monolayer of MoS 2 has the potential to become a good spin sink material when used with Co, 14 Co 2 FeAl, 15 Co 2 FeSi 16 and Ni 81 Fe 19 . 17,18 However, its compatibility with other potential FMs is yet to be explored. These properties of TMDs are essential for exploring new spin-based physics and developing energy-efficient ultrafast future spintronic devices.…”

Large Spin Hall Conductivity in Epitaxial Thin Films of Kagome Antiferromagnet Mn3Sn at Room Temperature

“…Figure 4a shows a representative ISHE signal, V ISHE (open circles) along with an ISHE signal measured from a Ta/Py/SiO 2 sample (inset). To eliminate contribution from self-induced ISHE and other rectification effects from Ni 80 Fe 20 , [32][33][34] the signal from a reference (Ni 80 Fe 20 ) sample is subtracted from the measured data (refer to Section S2, Supporting Information, for more details). The sign of signal obtained from Mn 3 Sn agrees with Ta, indicating a negative sign of 𝜃 SH .…”

Magnetic-Proximity-Induced Efficient Charge-to-Spin Conversion in Large-Area PtSe2/Ni80Fe20 Heterostructures

“…From this, we determine spin mixing conductance to be ∼7.6 × 10 19 m −2 , which is higher than those ofother TMD/ NiFe systems. 16,17 The lower value of α for d PtSed 2 = 5 nm is attributed to the lower van der Waals interaction observed in Raman measurements (see section S5 in the Supporting Information) for this sample. The inhomogeneous line width ΔH 0 is found to be similar for all the devices, ∼5 ± 3 Oe, indicating no significant degradation in the quality of the magnetic layer (NiFe) grown on PtSe 2 .…”

“…Significant efforts have been reported to improve the energy efficiency of HM-based SOT devices. − One method to achieve a higher SOT efficiency is to replace the HM layer with alternative materials that have a large charge-to-spin conversion efficiency and high conductivity. Transition metal dichalcogenides (TMDs) are potential replacements of HM due to various properties such as tunable conductivity, , high spin–orbit coupling, − the presence of Dzyaloshinskii–Moriya interaction, tunable band structure, , spin-layer locking, and long spin lifetime . The use of TMDs in SOT devices has shown a number of advantages, e.g., the ability to control SOT using the crystal symmetry − and electric field …”