Proximity-Induced Tunable Magnetic Order at the Interface of All-van der Waals-Layered Heterostructures

Abstract

Spin−orbit coupling (SOC) plays a crucial role in controlling the spin−charge conversion efficiency, spin torque, and complex magnetic spin structures. In this study, we investigate the interplay between SOC and ferromagnetism in heterostructures of large-SOC and magnetic materials. We highlight the importance of the SOC-proximity effect on magnetic ordering in all-van der Waals-layered heterostructures, specifically Fe 3 GeTe 2 (FGT)/monolayer W 1−x V x Se 2 (x = 0 and 0.05). By increasing the SOC strength, we demonstrate various magnetic orderings induced at the interface of the heterostructure, including spin-flop, spin-flip, and inverted magnetization. Moreover, we show a sharp magnetic switching from antiferromagnetic state to ferromagnetic state in FGT/W 0.95 V 0.05 Se 2 , which is characteristic of the synthetic antiferromagnetic structure. This proof-of-concept result offers the possibility of interface-tailoring spintronics, including two-dimensional magnetoresistive random access memory toggle switching. Our findings provide insight into the design and development of next-generation spintronic devices by exploiting the interplay between SOC and magnetic ordering in all-van der Waals-layered heterostructures.

Tailoring coercive fields and the Curie temperature via proximity coupling in WSe2/Fe3GeTe2 van der Waals heterostructures

“…It has been proposed that attaching a nonmagnetic layer with strong SOC to 2D magnets can effectively enhance the magnetic anisotropy [27]. Recent experiments involving analogous heterostructures [18,21] reveal the stabilization of 2D magnetism in thick FGT flakes, which is induced by the SOC proximity effect. Therefore, it is reasonable to ascribe the enhanced magnetic anisotropy to the SOC proximity effect.…”

“…For example, the Curie temperature of EuS film coupled with a topological insulator Bi 2 Se 3 can be immensely enhanced beyond bulk EuS, resulting from the strong SOC of Bi 2 Se 3 [25,28]. Recent experiments in the WSe 2 /Fe 3 GeTe 2 vdW heterostructure have revealed the SOC proximity effect through transport measurements [18,21]. However, no obvious improvement in the Curie temperature has been observed in this vdW nonmagnetic/ferromagnetic stack, which requires systematic experimental studies.…”

“…The examples mentioned above focus on the impact of magnetic layers on nonmagnetic semiconductors. Conversely, there is growing interest in modulating 2D magnets through adjacent nonmagnetic layers [18][19][20][21]. In 2D magnets, spinorbit coupling (SOC) from heavy elements is crucial for magnetic anisotropy, which sustains longrange magnetic order even at the monolayer limit [22,23].…”

“…In 2D magnets, spinorbit coupling (SOC) from heavy elements is crucial for magnetic anisotropy, which sustains longrange magnetic order even at the monolayer limit [22,23]. The combination of 2D magnets and materials with strong SOC can effectively enhance the magnetic anisotropy [21,[24][25][26][27], resulting in a modification of the magnetic order. For example, the Curie temperature of EuS film coupled with a topological insulator Bi 2 Se 3 can be immensely enhanced beyond bulk EuS, resulting from the strong SOC of Bi 2 Se 3 [25,28].…”

Strategy for transferring van der Waals materials and heterostructures

“…Transition metal dichalcogenides (TMDs), such as monolayer semiconductor 2H, metallic 1T, distorted metallic 1T' , and multilayer rhombohedral (3R) and orthorhombic (Td) phases [4], have extended the spectrum of 2D materials, fostering the exploration of unique physical phenomena. These materials have opened up avenues for studying strong Coulomb interactions, spinorbit coupling, carrier multiplication, hot carriers, Weyl semimetals, topological insulators, superconductivity, valleytronics, twistronics, and more [5][6][7][8][9][10][11][12][13][14][15]. Additionally, other 2D vdW-layered materials like insulating h-BN [16], thickness-dependent electrical properties of black phosphorus (BP) [17], and highly conductive MXene [18] have significantly expanded the library of vdW-layered materials, facilitating the development of transistors, optoelectronics, spintronics, photodetectors, and various sensors [19][20][21][22][23].…”