Direct Evidence of Spin Transfer Torque on Two-Dimensional Cobalt-Doped MoS₂ Ferromagnetic Material

Abstract

The manipulation of two-dimensional (2D) ferromagnetic materials by spin current is emerging as the central theme of 2D spintronics research. A paradigm of spintronic devices, the spin Hall magnetoresistance (SMR) device, has been elucidated to obtain direct evidence of spin transfer torque (STT) on a three-dimensional (3D) ferromagnet. Here, we present pioneering results on the SMR effect in a 2D cobalt-doped MoS2/Ta van der Waals heterostructure, confirming the existence of STT by the magnetic-field angle dependence of the resistance. Our study on the STT of 2D ferromagnetic materials indicates the feasibility of the realization of 2D spintronic devices.

Multiferroic materials based on transition-metal dichalcogenides: Potential platform for reversible control of Dzyaloshinskii-Moriya interaction and skyrmion via electric field

“…[30] By varying the coverage of the intercalated metal from low concentration to complete intercalation with the intercalated atoms occupying the octahedral vacancies between the two S layers, the magnetic properties can be tuned. In addition, experimental results have shown that CoMoS 2 present ferromagnetic properties with out-of-plane magnetization and Curie temperature T c around 100 K. [31] Herein, we propose that the bilayer TMDs can serve as an efficient platform for forming 2D multiferroic systems with intrinsic ME coupling, such as Co intercalated bilayer MoS 2 . The intercalated Co atoms not only introduce the magnetism but also induce ferroelectricity via formation of polar structure.…”

The Magnetic Genome of Two-Dimensional van der Waals Materials

“…445,447 SMR effects have been clearly observed in bilayers of the insulating 2D magnet Co-doped MoS 2 and Ta. 448 As mentioned above, the spin currents inducing SOT can be generated not only by the SHE of a 3D material as Pt but also from SOC effects in 2DEGs at interfaces or surfaces. An interesting example is given by the theory by Dolui et al 444 of the SOT acting on CrI 3 in the bilayer CrI 3 /monolayer TaSe 2 heterostructure shown in Figure 40c.…”

“…445 , 447 SMR effects have been clearly observed in bilayers of the insulating 2D magnet Co-doped MoS 2 and Ta. 448 …”

“…Interestingly, similar experiments of switching by current-induced SOT have been performed with nonconducting 2D magnets, for example on bilayers of CGT and Pt or Ta. − The SOT is detected by the Hall voltage ascribed to the introduction of spin polarization and AHE in Pt (Ta) by proximity with CGT. An alternative explanation is by the spin Hall magnetoresistance (SMR) associated with SOT, that is the dependence of the resistance of Pt (Ta) on the relative directions of the current and magnetization of CGT. , SMR effects have been clearly observed in bilayers of the insulating 2D magnet Co-doped MoS 2 and Ta …”

Spin Hall Magnetoresistance Effect from a Disordered Interface

“…The SMR effect has been observed in a system consisting of the van der Waals compound MoS 2 doped with Co impurities and Ta. 11 However, experimental studies of the SMR effect in proper layered magnets are lacking so far, while a variety of studies on magneto-transport behavior in van der Waals magnetic compounds interfaced with HMs (Ta, Pt, and W) have been reported, highlighting the importance of such heterostructures for spintronic applications. 12−17 We note here that, till date, most of such interfaces are assembled by sputtering of a HM layer on top of the selected van der Waals material, even though their structural characterization is scarcely reported.…”