Emergent Multifunctional Magnetic Proximity in van der Waals Layered Heterostructures

Abstract

Proximity effect, which is the coupling between distinct order parameters across interfaces of heterostructures, has attracted immense interest owing to the customizable multifunctionalities of diverse 3D materials. This facilitates various physical phenomena, such as spin order, charge transfer, spin torque, spin density wave, spin current, skyrmions, and Majorana fermions. These exotic physics play important roles for future spintronic applications. Nevertheless, several fundamental challenges remain for effective applications: unavoidable disorder and lattice mismatch limits in the growth process, short characteristic length of proximity, magnetic fluctuation in ultrathin films, and relatively weak spin-orbit coupling (SOC). Meanwhile, the extensive library of atomically thin, 2D van der Waals (vdW) layered materials, with unique characteristics such as strong SOC, magnetic anisotropy, and ultraclean surfaces, offers many opportunities to tailor versatile and more effective functionalities through proximity effects. Here, this paper focuses on magnetic proximity, i.e., proximitized magnetism and reviews the engineering of magnetism-related functionalities in 2D vdW layered heterostructures for next-generation electronic and spintronic devices. The essential factors of magnetism and interfacial engineering induced by magnetic layers are studied. The current limitations and future challenges associated with magnetic proximity-related physics phenomena in 2D heterostructures are further discussed.

Visualizing the Effect of Oxidation on Magnetic Domain Behavior of Nanoscale Fe3GeTe2 for Applications in Spintronics

“…The flexibility of the heterostructures that can be created enables a variety of novel functionalities that result from interfacial coupling, 10,11 for example, exchange bias, 12,13 and magnetic proximity effects. 14 This class of materials is therefore attracting broad interest due not only to enabling an understanding of fundamental physical phenomena but also to their potential as candidates for spintronic 15,16 and valleytronic 17 applications. Fe 3 GeTe 2 (FGT) has been extensively explored to understand its intrinsic magnetic, 2 electronic, 7 and optical 18 behaviors.…”

“…This unique structure and strong anisotropy, in addition to the different compositions and stackings that can arise, gives rise to rich emergent physical behaviors, for example, low-dimension-limit ferromagnetism, a broad range of magnetic spin textures, − and a Curie temperature that can be tuned by external stimuli such as thickness, strain, and ion irradiation. − VdW heterostructure stacks containing magnetic vdW materials can be easily engineered using mechanical-assembly and stacking, both by using the exfoliation method or by interfacing with thin films deposited using various sample growth methods. The flexibility of the heterostructures that can be created enables a variety of novel functionalities that result from interfacial coupling, , for example, exchange bias, , and magnetic proximity effects . This class of materials is therefore attracting broad interest due not only to enabling an understanding of fundamental physical phenomena but also to their potential as candidates for spintronic , and valleytronic applications.…”

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

“…Therefore, the interplay between SOC and (anti)­ferromagnetism through the SOC-proximity effect has attracted significant interest for its potential applications in next-generation spintronics, including spin–charge conversion, magneto-crystalline anisotropy, and magnetoresistive random access memory toggle switching. Recent works using the heterostructure with a strong SOC material and 2D magnet have focused on spin–orbit torque switching, modulation of chiral spin structure, and generation of spin-polarized currents. − However, the SOC-proximity effect on magnetic ordering in the magnetic layer has been rarely investigated.…”

Charge Transfer and Asymmetric Coupling of MoSe2 Valleys to the Magnetic Order of CrSBr

“…Furthermore, magnetic proximity effects have led to spin-dependent charge transfer and concomitant circularly polarized PL in hybrid devices based on both CrI 3 , and CrBr 3 . However, most previous studies in magnetic vdW heterointerfaces involved vdW ferromagnetic materials. − AFM materials have a variety of spin orderings with distinct magnetic symmetry groups which could result in unique magnetic properties, and therefore there are interesting ways to control their functionalities by choosing appropriate AFM materials …”